definiens: shall mean the specific prop rietary biological materials listed in Appendix 2 ( including Progeny and Unmodified Derivatives of th ose materials, but excluding Modifications except t o the extent they incorporate such materials ), which may be updated from time to time upon mutual writte n agreement of the Intellectual Property Office of CM CC and Licensee . For purposes of this definition, Progeny shall mean an u nmodified descendant from the material, such as a v irus from virus, cell from a cell, or organism from an organism ; Unmodified Derivative s shall mean substances created by the Licensee which constitute an unmodified functional subunit o r product expressed by the original material ( such as subclones of unmodified cell lines, purified or fra ctionated subsets of the original material, protein s expressed by DNA / RNA, or monoclonal antibodies secr eted by a hybridoma cell line ) ; and Modifications shall mean substa nces created by the Licensee which contain or incor porate the material