Biologics are often described as vaccines, blood products (including blood) and allergenics. Since the late 1940s, however, the types of products that are biologics have been expanding. The advent of modern biotechnology methods in the last 25 years has contributed dramatically to this expansion. Hybridoma and recombinant DNA methods, gene and cellular therapies, and newer technologies, such as the cloning method involved in the creation of Dolly the Sheep in 1996, have challenged traditional notions of what are biologics. The new technologies also have recently resulted in questions of by whom and how biologics should be regulated vis-à-vis other drugs handled by the Center for Drug Evaluation and Research (CDER) or the Center for Veterinary Medicine (CVM).