The results showed that there were no remarkable differences in serum AFP (p = 0.311) and CA125 (p = 0.377) levels between the T2DM + CRC group and the T2DM group, but CEA (p < 0.001) and CA199 (p = 0.016) levels were notably enhanced in the T2DM + CRC group (Table 1). Here, AFP is linked to type 2 diabetes mellitus.