PRDM1 and influenza: Gene ontology (GO) and hallmark pathway analysis revealed a differential regulation of cytokine-mediated signaling pathway in influenza-infected CD4+ T cells between Prdm1-CKO and WT mice (Fig. 3B), with enrichment of IL-2–STAT5 signaling in influenza-infected CD4+ T cells from Prdm1-CKO mice compared to WT mice (Fig. 3, C and D), suggesting that BLIMP1 repressed IL-2 signaling in influenza-infected CD4+ T cells.