In the case of hepatocellular carcinoma (HCC), inhibition of CDK5 expression also inhibits its angiogenesis, which reduces the presence of the hypoxia-inducible factor 1a (HIF-1a), a protein that mediate cellular adaptation to hypoxia, which gives hope for an effective method of curing this type of cancer and other highly vascularized cancers [221]. Here, HIF1A is linked to cancer.