KRAS and colorectal carcinoma: The addition of curcumin to regorafenib augmented apoptosis and autophagy rates in HCT116 (KRAS mutant) but not in HT-29 cells (KRAS wild-type), thus suggesting that curcumin functions as a MEK inhibitor to induce a synthetic lethal effect on KRAS-mutant CRC cells receiving the targeted drug regorafenib.