TP53 and malignant colon neoplasm: In addition, CK1δ can phosphorylate MDM2, reduce its interaction with p53, and further stabilize and activate p53 46.However, the effect of CK1ε/δ inhibitors IC261 on the expression of p53 in colon cancer cells remains unclear.Our results show that IC261 can significantly reduce the level of p53 protein in colon cancer cells.