IL6 and infection: Mouse studies have shown that the generation of Tfh cells during response to TD vaccines or infection is regulated by cytokines that promote (IL-6 and IL-21) and limit (IL-2) Tfh expansion.37 The augmentation of Tfh response by IL-6 is mediated by the suppression of IL-2 Rβ on Tfh cells which in turn protects Tfh cells from the detrimental signals elicited by IL-240 (Figure 1(b)).