Common and specific telomere abnormalities between HBV-, HCV-, and alcohol-associated cirrhosis and hepatocellular carcinoma. A. Distribution of hTERT and hTER expression, telomerase activity and TRF length among the main causes of hepatocellular carcinoma. B. Alteration in shelterin and non-shelterin gene expression at the two main steps of liver carcinogenesis in vivo. Significantly overexpressed genes (p < 0.05, Mann Whitney test) are represented in black whereas significantly underexpressed genes are represented in gray.