PIK3CA and cytomegalovirus infection: Among these KEGG pathways, those related to cancer (hsa05200), PI3K-Akt signaling pathway (hsa04151), proteoglycans in cancer (hsa05205), microRNAs in cancer (hsa05206), human cytomegalovirus infection (hsa05163), human papillomavirus infection (hsa05165), endocrine resistance (hsa01522), chemical carcinogenesis—receptor activation (hsa05207), EGFR tyrosine kinase inhibitor resistance (hsa01521), MAPK signaling pathway (hsa04010), and human T-cell leukemia virus 1 infection (hsa05166) have been shown to have clear links with liver cancer occurrence.