In our study, we investigated the effects of five IL1A variants (rs3783550, rs3783546, rs2856838, rs1609682, and rs3783521) on the susceptibility to CRC, which is supposed to provide more evidence for IL1A in CRC pathogenesis and contribute to early CRC risk estimation among the individuals of Chinese Han ancestry. The gene discussed is IL1A; the disease is colorectal carcinoma.