CDKN2A and hepatocellular carcinoma: While CDKN2A transcripts levels were upregulated in most of the analyzed tumors, the assessment of protein expression revealed that only four tumors, namely UCEC, KIRC, LUAD, and LUSC, experienced upregulation in CDKN2A protein levels in cancerous tissues versus control while two tumors, namely HCC and HNSC, experienced the opposite pattern.