PCNA and hepatocellular carcinoma: proliferating cell nuclear antigen antisense RNA1 (PCNA- AS1) promotes tumor cell growth and is highly up-regulated in this type of cancer while LncRNA-down-regulated expression by hepatitis B virus X-HBx- protein (DREH) is down-regulated especially in HBV-related HCC tissues and is also dramatically decreased in HCC patients with poor prognosis [89-91].