PIK3CA and head and neck squamous cell carcinoma: Since genes known to be commonly mutated in HNSCC did not come up among the top genes in our analysis, we specifically analysed two genes known for hotspot mutations in HPV+ TSCC/BOTSCC/OPSCC—FGFR3 and PIK3CA. Additionally, we checked for mutations in the TP53 gene to see whether TP53 mutations are enriched among relapses.