USP7 and hepatocellular carcinoma: TMEM43 was shown to be highly expressed in HCC and the absence of TMEM43 in cancer cells has been reported to have a negative association with HCC progression via ubiquitin-specific protease 7 (USP7) and voltage-dependent anion channel 1 (VDAC1), a protein that regulates entry of molecules into the outer mitochondrial membrane.