PRDM1 and influenza: Nevertheless, we found higher expression of CD25 (Fig 2, B and C), CD122 (Fig. 2, D and E), and phospho-STAT5 (pSTAT5) (Fig. 2, F and G) in all populations (TFH, TFR, cTreg, and TEFF cells) in the medLNs of influenza-infected Prdm1-CKO mice as compared to WT mice.