PIK3CA and infection: Specifically, it was reported that far fewer mutations was found in HPV-positive tumors than that of negative ones especially of those genes including TP53, CDKN2A, PTEN, PIK3CA, FBXW7, HRAS and NOTCH1, which involve in various crucial cellular signaling pathways such as EGFR, PI3K-AKT and mTOR [21, 22]; 3) Patients with HPV-positive infection are usually younger and have more favorable epidemiological, performance status, and other clinical and histopathological features [23].