CD8A and colorectal carcinoma: Finally, when Saccharofermentanaceae acted as a protective factor against CRC, CD40 on monocytes (2.35%), central memory CD4+T cells (5.76%), and CD28 on CD28+CD45RA+CD8+T cells (5.00%) mediated its genetic predictive effect on CRC risk (Table 3; Supplementary Material S12).