Depletion of systemic and tissue-specific retinoic acid levels are associated with possible malignant transformation; thus, chronic alcohol consumption reduces hepatic vitamin A and retinoic acid levels, which are strongly related to the later development of hepatocellular carcinoma (HCC) via decreasing mitogen-activated protein kinase (MAPK) and increasing levels of phosphorylated c-Jun N-terminal kinases (JNKs) [48]. Here, JUN is linked to hepatocellular carcinoma.