CYP7B1 and hepatocellular carcinoma: However, expression of genes involved in sterol catabolism (CYP8B1, CYP27A1, CYP7B1, CYP39A1) and sterol efflux (ABCA1, ABCG5, ABCG8) was significantly reduced in HCC tissues implying that sterols accumulate in HCC (Lu et al., 2013).