A TP53 mutation was found exclusively in the CMTC part, while the poorly differentiated component showed a clonal evolution, harboring an activating PIK3CA mutation and copy number gains of BRCA2, FGF23, FGFR1, and PIK3CB—alterations which are typically seen in squamous cell carcinoma. The gene discussed is FGF23; the disease is squamous cell carcinoma.