TLR4 and colorectal cancer: However, R. gnavus produces a pro‐inflammatory polysaccharide, glucorhamnan, that is recognized by innate immune cells via toll‐like receptor 4 (TLR4).[58] MICAH revealed that tumors containing R. gnanus showed enrichment of genes that are required for TLR‐mediated signaling, the cyclin‐dependent protein kinases pathway.[59] Furthermore, guided by the finding by MICAH, we experimentally validated the role of Blautia in modulating the response to anti‐PD1 therapy in colorectal cancer.