PTTG1 and colonic neoplasm: Various in vivo studies showed that fisetin alone performed anticancer activities against human colon cancer cell lines (CT‐26 and HCT116) and markedly down‐regulated the level of the oncoprotein securin in a p53‐independent manner, whereas fisetin in combination with 2‐Gy radiation did not significantly suppress securin‐null HCT116 tumor growth compared with normal HCT116 tumors (Leu et al., 2016).