Somatic mutation analysis of our uRCC cohort demonstrated that potentially mTORC1 pathway activating mutations comprising MTOR (5), TSC1 (4), TSC2 (3) and PTEN (4) occurred mutually exclusively in 16 (26%) cases, which might indicate another distinct subset (Fig. 3a). This evidence concerns the gene PTEN and Unclassified Renal Cell Carcinoma.