CD4 and influenza: Investigating the chromatin organizer Satb1, several studies have shown that TGFβ stimulation of murine T cells silences Satb1 expression, which in turn promotes Tfh differentiation (40, 69) Using a TCR transgenic TGFβRII CD4+ T cells conditional-KO reveals that in vivo generation of Tfh following influenza infection required TGFβ signaling on T cells.