IL17A and colitis: Next, we analyzed CD4 T-cell subsets and found a significant increase in IL-17A–producing CD4+ cells from the mesenteric LNs (MLNs) of CD4CreTTPf/f mice compared to WT mice, whereas the frequency of IFN-γ–producing CD4+ T cells was comparable (Figures 6B,C), further suggesting that IL-17 produced by the TH17 cells may contribute to the colitis in CD4CreTTPf/f mice.