Sarcomatoid RCC (SRCC) of different parent subtypes (SccRCC, SPapRCC, and SChRCC) demonstrates (A) similar mutational burdens compared to non-sarcomatoid RCC (RCC) of different parent subtypes (ccRCC, PapRCC, and ChRCC). SRCCs segregate according to parent subtype, as shown by an unsupervised clustering analysis of (B) copy number, 1500 top genes; and (C) mRNA expression, 1000 genes. (D) Mutations of 3p21–25 tumor suppressor genes are confined to SccRCC.