The use of human fetal tissue in biomedical research and development has led to lifesaving medical advances over the last several decades, including the development of the polio vaccine and interventions to treat and prevent HIV infection. In the field of research on HIV—which affects 37 million people worldwide—there is simply no alternative to the deployment of a humanized mouse model, made possible with the use of human fetal tissue, in the testing of experimental therapies. Efforts to undermine or halt this work will inevitably slow, or at worst cripple, the development of promising therapies with the potential to cure HIV and save millions of lives worldwide. While attempts to explore alternatives to the use of human fetal tissue may be worth pursuing, they should not provide the pretext for abandoning the only method currently available to researchers for testing the viability of experimental treatments in an animal model. While we appreciate the Administration’s commitment to achieving the goals of the National HIV/AIDS Strategy, we urge them in the strongest possible terms to continue permitting fetal tissue research, which could well hold the key to curing an infection that has already claimed 35 million lives.