This Agreement shall be binding upon and shall inure to the benefit of the Parties and their respective permitted assigns and successors. Neither this Agreement nor any of the rights, interests or obligations set forth in, arising under or created by this Agreement may be assigned by any of the Parties without the prior written consent of the other Parties, except that each of the Investors may, without the consent of the Company, assign all or a portion of its rights, interests and funding obligation hereunder to one or more of their respective Affiliates, but only to Affiliates that are U.S. Citizens;  provided  that any such assignment shall not relieve any of the Investors of its funding obligation hereunder on the Closing Date. In the event of an assignment to such an Affiliate, such Affiliate shall become party to this Agreement by execution of a joinder hereto in form and substance reasonably acceptable to the Company. Any assignment or transfer in violation of this  Section 6.12  shall be null and void.