For example, terms such as “peptidyl-serine phosphorylation”, “peptidyl-threonine phosphorylation”, “positive regulation of MAPK cascade”, etc. explains the biology where the activating mutations in RTKs, EGFR, PIK3CA, etc. has been observed, common in HNSCC HPV-negative patients. This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.