GSTA4 and colitis: However, in the absence of Il10, colonic macrophages can be polarized by certain commensals, for example, E. faecalis and E. coli, leading to inflammation and CRC.3,39 Compared to Il10−/− mice, Gsta4−/− mice (with intact Il10) did not develop colitis after 9-month colonization with E. faecalis, suggesting a primary role of M1-polarized macrophages in E. faecalis-induced CRC.