ABCB1 and colonic neoplasm: The Wnt/β-catenin signaling pathway is the upstream regulatory pathway of some drug resistance proteins, such as the ATP-binding cassette subfamily B member 1 (ABCB1), multidrug resistance 1 (MDR1), and p-glycoprotein (P-gp), which constitute important molecular mechanisms involved in the occurrence, development, metastasis, and chemotherapy resistance of colon cancer and other tumors.