Common use of Restrictions on Transferability; Restrictive Legend Clause in Contracts

Restrictions on Transferability; Restrictive Legend. The holder acknowledges that the shares of Common Stock issuable upon exercise of this Warrant are subject to restrictions under applicable Federal and state securities laws. Each certificate representing shares of Common Stock issued shall, upon the exercise of this Warrant, bear the following legends in addition to such other restrictive legends as may be required by law: "The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended (the "ACT"), or any state securities laws, and no sale or transfer thereof may be effected without an effective registration statement or an opinion of counsel for the holder, satisfactory to the Company, that such registration is not required under the Act and any applicable state securities laws." Dated: January 19, 1999 GENETIC VECTORS, INC. By:_________________________________________ Title:______________________________________ AGREED TO AND ACCEPTED: CAPITAL RESEARCH LTD. By:_________________________________ Its:________________________________ Date:_______________________________

Restrictions on Transferability; Restrictive Legend. The holder Holder acknowledges that the shares of Common Stock issuable upon exercise of this Warrant are subject to restrictions under applicable Federal and state securities laws. Each certificate representing shares of Common Stock issued shall, upon the exercise of this Warrant, bear the following legends in addition to such other restrictive legends as may be required by law: "The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended (the "ACT"), or any state securities laws, and no sale or transfer thereof may be effected without an effective registration statement or an opinion of counsel for the holderHolder, satisfactory to the Company, that such registration is not required under the Act and any applicable state securities laws." Dated: January 19March 9, 1999 GENETIC VECTORS, INC. By:_________________________________________ Title:______________________________________ AGREED TO AND ACCEPTED: CAPITAL RESEARCH STERLING TECHNOLOGY PARTNERS, LTD. By:_________________________________ Its:________________________________ Date:_______________________________

Restrictions on Transferability; Restrictive Legend. The holder Holder acknowledges that the shares of Common Stock issuable upon exercise of this Warrant are subject to restrictions under applicable Federal and state securities laws. Each certificate representing shares of Common Stock issued shall, upon the exercise of this Warrant, bear the following legends in addition to such other restrictive legends as may be required by law: "The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended (the "ACT"), or any state securities laws, and no sale or transfer thereof may be effected without an effective registration statement or an opinion of counsel for the holderHolder, satisfactory to the CompanyCompany and its counsel, that such registration is not required under the Act and any applicable state securities laws." Dated: January 19April 4, 1999 2000 GENETIC VECTORS, INC. By:_________________________________________ : ------------------------------------ Title:______________________________________ : ------------------------------------ AGREED TO AND ACCEPTED: CAPITAL RESEARCH LTD. [LENDER] By:_________________________________ : --------------------------------- Its:________________________________ : -------------------------------- Date:_______________________________: -------------------------------

Restrictions on Transferability; Restrictive Legend. The holder Holder acknowledges that the shares of Common Stock issuable upon exercise of this Warrant are subject to restrictions under applicable Federal and state securities laws. Each certificate representing shares of Common Stock issued shall, upon the exercise of this Warrant, bear the following legends in addition to such other restrictive legends as may be required by law: "The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended (the "ACT"), or any state securities laws, and no sale or transfer thereof may be effected without an effective registration statement or an opinion of counsel for the holderHolder, satisfactory to the CompanyCompany and its counsel, that such registration is not required under the Act and any applicable state securities laws." Dated: January 19June 9, 1999 2000 GENETIC VECTORS, INC. By:_________________________________________ : ----------------------------------------- Title:______________________________________ : Mead McCabe, Jr., Chief Executive Oxxxxex AGREED TO AND ACCEPTED: CAPITAL RESEARCH LTD. -------------------------------- By:_________________________________ Its:________________________________ : ----------------------------- Name: --------------------- Title: -------------------- Date:_______________________________: ---------------------------

Restrictions on Transferability; Restrictive Legend. The holder acknowledges that the shares of Common Stock issuable upon exercise of this Warrant are subject to restrictions under applicable Federal and state securities laws. Each certificate representing shares of Common Stock issued shall, upon the exercise of this Warrant, bear the following legends in addition to such other restrictive legends as may be required by law: "The shares represented by this certificate have not been registered under the Securities Act of 1933, as amended (the "ACT"), or any state securities laws, and no sale or transfer thereof may be effected without an effective registration statement or an opinion of counsel for the holder, satisfactory to the Company, that such registration is not required under the Act and any applicable state securities laws." Dated: January 19, 1999 GENETIC VECTORS, INC. By:_________________________________________ Title:______________________________________ AGREED TO AND ACCEPTED: CAPITAL RESEARCH STERLING TECHNOLOGY PARTNERS, LTD. By:_________________________________ Its:________________________________ Date:_______________________________