CD4 and colitis: Notably, rapamycin treatment in CD4+ T-cell transfer model of colitis increases the differentiation of Th1 cells in mesenteric lymph nodes (Kurebayashi et al. 2012), possibly due to both T-cell intrinsic deviation to Th1 development and the increased production of IL-12 from APCs in the absence of PI3K-Akt-mTORC1 pathway (Fukao et al. 2002; Ohtani et al. 2008; Weichhart et al. 2008).