definiens: shall mean any United States or foreign patent applications or patents owned, or licensed on a royalty -free basis with the right to sublicense, by ENZON or its AFFILIATES containing one or more c laims to SCA DISCOVERIES, any continuation -in - part, division, or continuation application thereof, any patent or the equivalent thereof granted thereon, and any reissue, reexamination, or extension of any of these patent(s ) including any applications filed and patent(s ) granted on ENZON IMPROVEMENTS ; PROVIDED, HOWEVER, that PATENT RIGHTS shall not include any claim in patent applications to specific SCA PROTEIN, or to any specific genetic sequence or host coding for or containing such genetic sequence codin g for a specific SCA PROTEIN, or to the therapeutic or diagnostic use of such a specific SCA PROTEIN . Existing PATENT RIGHTS are listed in Appendix I, which shall be modified by ENZON from time -to - time so that it accurately reflects those patent applicatio ns and patents includable under PATENT RIGHTS during the term of the Agreement, relevant to the FIELD