TGFBR2 and head and neck squamous cell carcinoma: HPV negative HNSCC (HPV- HNSCC) tumors frequently harbor alterations in TP53 and CDKN2A, although several other tumor suppressor genes are also commonly mutated (FAT1, NOTCH1, KMT2D, NSD1, and TGFBR2) [2, 13].