Knockout of FOXO3a inhibited the autophagy induced by sorafenib itself in normoxia and significantly enhanced the cytotoxicity of sorafenib in HCC cells; and it also inhibited the hypoxia-induced autophagy and achieved the same effect in sorafenib sensitivity-enhancement in HCC cells as it in normoxia. Here, FOXO3 is linked to hepatocellular carcinoma.