UNITED STATES

SECURITIES AND EXCHANGE
COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Item 1.

Security and Issuer

The class of securities to which this Schedule 13D relates is Common Stock, par value $0.001 per share (“Common Stock”) of BTHC VI, Inc., a Delaware corporation (the “Issuer”).  The principal executive offices of the Issuer are located at 3201 Carnegie Avenue, Cleveland, Ohio  44115-2634.

Item 2.

Identity and Background

(a)

This Schedule 13D is being filed jointly by (i) Daniel C. Lubin, (ii) Jordan S. Davis, (iii) Radius Venture Partners II, LLC, (iv) Radius Venture Partners III, LLC, (v) Radius Venture Partners II, L.P., (vi) Radius Venture Partners III, L.P. and (vii) Radius Venture Partners III QP, L.P. (collectively, the “Filing Parties”).(1)  Radius Venture Partners II, LLC is the general partner of Radius Venture Partners II, L.P.  Radius Venture Partners III, LLC is the general partner of Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P.  Messrs. Lubin and Davis are the managing members of Radius Venture Partners II, LLC and Radius Venture Partners III, LLC.

(b)

The business address of each of the Filing Parties is 400 Madison Avenue, 8th Floor, New York, NY  10017.

(c)

The principal occupation of Messrs. Lubin and Davis is private equity investing and portfolio company management with respect to Radius Venture Partners II, L.P., Radius Venture Partners III, L.P., Radius Venture Partners III QP, L.P. and other private equity funds.  The principal business of Radius Venture Partners II, LLC is to manage Radius Venture Partners II, L.P.’s private equity investments.  The principal business of Radius Venture Partners III, LLC is to manage the private equity investments of Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P.  The principal business of Radius Venture Partners II, L.P., Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P. is to hold private equity investments.

(d)

During the last five years, none of the Filing Parties has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e)

During the last five years, none of the Filing Parties has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction resulting in his or its being subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f)

The citizenship of each of the Filing Parties is as follows:

·       Daniel C. Lubin is a United States citizen

·       Jordan S. Davis is a United States citizen

·       Radius Venture Partners II, LLC is a Delaware limited liability company

·       Radius Venture Partners III, LLC is a Delaware limited liability company

·       Radius Venture Partners II, L.P. is a Delaware limited partnership

·       Radius Venture Partners III, L.P. is a Delaware limited partnership

·       Radius Venture Partners III QP, L.P. is a Delaware limited partnership

(1)  Neither the present filing nor anything contained herein shall be construed as an admission that any Filing Party constitutes a “person” for any purpose other than Section 13(d) of the Securities Act.

Item 3.

Source and Amount of Funds or Other Consideration

Each of Radius Venture Partners II, L.P., Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P. (collectively, the “Radius Entities”) is a limited partnership which acquired, respectively, 800,000; 103,766 and 696,234 shares (the “Shares”) of Common Stock of the Issuer and 400,000; 51,883 and 348,117 warrants to purchase Common Stock (the “Warrants”, and together with the Shares, the “Securities”) of the Issuer for investment purposes on June 8, 2007 for cash.  The cash was provided by the capital contributions of the partners of the Radius Entities.  The Radius Entities acquired the Securities pursuant to that certain Securities Purchase Agreement, dated as of June 8, 2007 (the “Securities Purchase Agreement”), by and among the Issuer, Athersys, Inc., and the Radius Entities and other investors party thereto.  Pursuant to the terms of the Securities Purchase Agreement, the Issuer sold 13 million shares of Common Stock at $5.00 per share to institutional and accredited investors, for a total of $65 million.  In connection with this transaction, Jordan S. Davis also received a grant of an option to purchase 75,000 shares of the Common Stock of the Issuer, vesting 50%/25%/25% over three years in quarterly increments.

Item 4.

Purpose of Transaction

The Radius Entities acquired the Securities for investment purposes.  Jordan S. Davis is a member of the Issuer’s Board of Directors, which plans to authorize the Issuer’s name change to Athersys, Inc. as soon as reasonably practicable.

Other than as discussed herein, the Filing Parties currently have no plans or proposals which would relate to or would result in:

(a)

The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer;

(b)

An extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries;

(c)

A sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries;

(d)

Any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board;

(e)

Any material change in the present capitalization or dividend policy of the Issuer;

(f)

Any other material change in the Issuer’s business or corporate structure;

(g)

Changes in the Issuer’s certificate of incorporation, by-laws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person;

(h)

Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association;

(i)

A class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934; or

(j)

Any action similar to any of those enumerated above.

The Filing Parties intend to evaluate their investment in the Issuer continuously and may, based on any such evaluation, determine at a future date to change their current position with respect to any action enumerated above.

Item 5.

Interest in Securities of the Issuer

The Filing Parties may be deemed to be members of a group for purposes of this Schedule 13D.

(a)

As of the date hereof, (i) Radius Venture Partners II, L.P. is the beneficial owner of 1,200,000 shares of Common Stock (400,000 of which are warrants to acquire Common Stock) (the “Radius II Shares”), or approximately 6.2% of the Issuer’s outstanding Common Stock, (ii) Radius Venture Partners III, L.P. is the beneficial owner of 155,649 shares of Common Stock (51,883 of which are warrants to acquire Common Stock) (the “Radius III Shares”), or approximately 0.8% of the Issuer’s outstanding Common Stock, (iii) Radius Venture Partners III QP, L.P. is the beneficial owner of 1,044,351 shares of Common Stock (348,117 of which are warrants to acquire Common Stock) (the “Radius III QP Shares”), or approximately 5.4% of the Issuer’s outstanding Common Stock and (iv) Mr. Davis is the beneficial owner of 75,000 shares of Common Stock (the “Davis Shares”), or approximately 0.4% of the Issuer’s outstanding Common Stock, by virtue of an option grant to purchase 75,000 shares of Common Stock, vesting 50%/25%/25% over three years in quarterly increments.  Each of Radius Venture Partners II, LLC and Messrs. Lubin and Davis may be deemed to also beneficially own the Radius II Shares as a result of their direct or indirect control of Radius Venture Partners II, L.P.  In addition, each of Radius Venture Partners III, LLC and Messrs. Lubin and Davis may be deemed to also beneficially own the Radius III Shares and the Radius III QP Shares as a result of their direct or indirect control of Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P.  Each of Radius Venture Partners II, LLC, Radius Venture Partners III, LLC and Messrs. Lubin and Davis disclaims all such beneficial ownership, except to the extent of its or his pecuniary interest in the Radius II Shares, the Radius III Shares or the Radius III QP Shares, as the case may be.

(b)

Radius Venture Partners II, L.P. has the sole power to vote or direct the vote and to dispose or direct the disposition of the Radius II Shares.  Messrs. Lubin and Davis, by virtue of their positions as managing members of the general partner of Radius Venture Partners II, L.P., may be deemed to have the shared power to vote or direct the vote of and shared power to dispose or direct the disposition of the Radius II Shares.

Radius Venture Partners III, L.P. has the sole power to vote or direct the vote and to dispose or direct the disposition of the Radius III Shares, and Radius Venture Partners III QP, L.P. has the sole power to vote or direct the vote and to dispose or direct the disposition of the Radius III QP

Shares.  Messrs. Lubin and Davis, by virtue of their positions as managing members of the general partner of Radius Venture Partners III, L.P. and Radius Venture Partners III QP, L.P., may be deemed to have the shared power to vote or direct the vote of and shared power to dispose or direct the disposition of the Radius III Shares and the Radius III QP Shares.

Mr. Davis has the sole power to vote or direct the vote and to dispose or direct the disposition of the Davis Shares.

(c)

The information provided in Item 3 is hereby incorporated by reference herein. 

(d)

Except as described herein, no other person is known by the Filing Parties to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, Common Stock beneficially owned by the Filing Parties.

(e)

Not applicable.

Item 6.

Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

The information provided or incorporated by reference in Item 2 and Item 3 is hereby incorporated by reference herein.

Item 7.

Material to Be Filed as Exhibits

A.

Joint Filing Statement (filed herewith).

RADIUS VENTURE PARTNERS II, L.P.

By: Radius Venture Partners II, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III, L.P.

By: Radius Venture Partners III, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III QP, L.P.

By: Radius Venture Partners III, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS II, LLC

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III, LLC

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

/s/ Jordan S. Davis

Jordan S. Davis

/s/ Daniel C. Lubin

Daniel C. Lubin

RADIUS VENTURE PARTNERS II, L.P.

By: Radius Venture Partners II, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III, L.P.

By: Radius Venture Partners III, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III QP, L.P.

By: Radius Venture Partners III, LLC,

its General Partner

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS II, LLC

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

RADIUS VENTURE PARTNERS III, LLC

By:

/s/ Jordan S. Davis

 Jordan S. Davis

 Managing Member

/s/ Jordan S. Davis

Jordan S. Davis

/s/ Daniel C. Lubin

Daniel C. Lubin