Knockdown of CDK2‐associated cullin domain 1 (CAC1), an innovative regulator of cell cycle, could promote the sensitivity of SW480/5‐FU and LoVo/5‐FU cell lines to 5‐FU by inducing cell apoptosis, arresting tumor cells at the G1/S phase, and lowering the expression of P‐gp and MRP‐1.48 Here, PGP is linked to neoplasm.