We evaluated histologically confirmed preinvasive and invasive OSSN for the presence of viral (HPV, EBV, MCPyV, KSHV, and adenovirus) DNA and HR-HPV genotypes and expressed proteins (EBNA1, p16, and MCPyV LT) for HPV, EBV, and MCPyV infection within tumor tissue. This evidence concerns the gene CDKN2A and neoplasm.