PIK3CA and head and neck squamous cell carcinoma: This analysis highlighted significant differences in expression levels of several disease-associated genes between the control and HNSCC groups, including TP53, MET, NOTCH1, PTEN, PIK3CA, EGFR, CDKN2A, BRCA1, BRCA2, BRAF, and PALB2 (Figure 6A).