Interestingly, the colon polyps (LIP) in the AOM-DSS treated Gpr15-KO mice showed distinct (e.g., increased MDSCs) as well as shared (e.g., increased IL-17A+ CD4+ and IL-17A+ CD8+ T cells) immune features of human CRC with reduced GPR15 expression. Here, GPR15 is linked to infectious otitis media.