CDKN2A and renal cell carcinoma: Genomic profiling reveals recurrent mutations in TP53, BAP1, and CDKN2A in sarcomatoid RCC, and NF2, SETD2, or ALK/NTRK fusions in unclassified RCC, indicating convergent pathways of dedifferentiation, chromatin remodeling, and cell-cycle dysregulation.