definiens: means th e document which is executed between RegeneRx and Sigma - Tau Finanziaria SpA, an Affiliate of [COMPANY], that guarantees the performance of and assumes certain o f the responsibilities of [COMPANY], or its Affiliates, should [COMPANY], or it s Affiliates, breach or fail to perform under the Agreement . It is understood th at such responsibilities shall not include the requirement by Sigma - Tau Fina nziaria SpA to * * * . In the event Sigma - Tau Finanziaria SpA does not * * * then t his Agreement shall terminate as provided hereunder, and Sigma - Tau Finanziaria Sp A shall assume all termination obligations and liabilities to which De fiante, or its Affiliates, would be subject * * * . The Warranty and Undertaking is described in Attachment D, which is made a part hereof by reference