TAT and AIDS: This makes it quite plausible that HIV Tat proteins secreted from infected follicular T helper cells shape B cell physiology in the germinal centers, providing a missing link between HIV infection and its contribution to the unusually high frequency of mutations in the HIV broadly neutralizing antibodies that arise from multiple rounds of germinal center mutation and selection (24) and contributing to the persistent high risk of lymphomagenesis in AIDS patients in the post-ART era.