CD4 and inflammatory bowel disease: Furthermore, the expression levels of the IFN-γ transcripts from the pro-inflammatory Th1 subset were significantly lower in the CD4+CD25− cells of the IBD model from K2P5.1−/− mice than from K2P5.1+/+ mice (Figure 5A), and no significant differences were noted in the expression levels of IL-17 in CD4+CD25− cells and IL-10 in CD4+CD25+ cells between IBD models from K2P5.1+/+ and K2P5.1−/− mice (Figures 5B,C).