In this study, the effects of compound Sophora injection on the expression of P-gp, ANXA1, ABCG2, and other drug-resistance proteins in drug-resistant colorectal cancer cell lines (fluorouracil (5-FU)/SW480 and oxaliplatin (L-OHP)/SW480) were studied [5–7], as were its effects on MDR, and the reversal mechanism was examined. The gene discussed is PGP; the disease is colorectal cancer.