MSI2 and malignant colon neoplasm: To further characterize the MSI2-dependent cancer cell inhibition of palmatine, we firstly examined palmatine in a dose-course assay, and confirmed the different responses between wild-type and MSI2 knockout HCT116 cells (Figure 5A), although palmatine exerted a weaker inhibition than Ro 08-2750 on the proliferation of colon cancer HCT116, RKO, and SW480 cells (Figure 5C).