The Food and Drug Administration (FDA) is publishing a guidance entitled "Q5A Viral Safety Evaluation of Biotechnology Products Derived From Cell Lines of Human or Animal Origin." The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance describes the testing and evaluation of the viral safety of biotechnology products derived from characterized cell lines of human or animal origin, and outlines data that should be submitted in marketing applications.