Hepatocellular carcinoma mouse models: Hepatitis B virus-associated hepatocarcinogenesis and haploinsufficient tumor suppressor genes

Figure 2 Tumor suppressor genes in hepatocellular carcinoma. A: Recessive tumor suppressor genes (TSGs) need there to be loss-of-function via two hits (mutation or genetic modification) in order to trigger tumor formation. Only when there is homozygous deficiency of a recessive TSG does this lead to hepatocellular carcinoma (HCC) development; B: Haploinsufficient TSGs are functionally insufficient to suppress tumor development when there is loss of only a single allele. Heterozygous deficiency of a haploinsufficient TSG can cause HCC development in the liver even when the second allele remains intact.