PKM and colorectal cancer: In tumor tissues, the proliferation of tumor cells was through K433 site of PKM2, and tannin selectively inhibits the pyruvate kinase activity of PKM2, rather than protein kinase activity and PKM2 expression, to suppress colorectal cancer cell proliferation, tannin is a promising PKM2 inhibitor for prevention of colorectal cancer [83] Ethyl pyruvate also has a good inhibitory effect on PKM, it is safe for red blood cells and easy to penetrate the blood-brain barrier [56].