CD4 and colorectal carcinoma: Although we found no changes in the frequency of CD25+ CD127- CD4+ T cells (Treg) in tumor versus control tissue in our human CRC data, we observed a significant increase in Treg frequency in the LIP of Gpr15-KO mice compared with Gpr15-Het mice, reflecting increased tumor burden in AOM-DSS treated Gpr15-KO mice.