The elevated levels of INSIG2 in livers and hepatoma cells with ablated Tial1 are likely responsible for inhibiting the proteolytic processing of SREBP1 and SREBP2, as shown by increased levels of pSREBPs and reduced nSREBPs, and the marked reduction in the levels of mRNAs encoding enzymes required for the synthesis of cholesterol, fatty acids, and triglycerides. This evidence concerns the gene INSIG2 and hepatocellular carcinoma.