CD4 and adenoma: As shown in Figure 3C, the CD4+CCR6+ Th17 cell proportion decreased in CRC when compared with the healthy control group (23.1 vs. 11.2, P = 0.0279) or adenoma grade I (24.3 vs. 11.2, P = 0.0163) or even adenoma grade II (21.7 vs. 11.2, P = 0.0042).