CD4 and colitis: To confirm that Cnb1 deletion in CD11chighMHCII+ cells did not impact T-cell function in vivo, we monitored the development of colitis following adoptive transfer of naïve CD4+CD45RBhighCD25− T cells from Cnb1CD11c and Cnb1fl/fl mice into immune-deficient Rag2KO mice16.