TSC1 and nonpapillary renal cell carcinoma: Our finding of low incidence of NF2 mutations in ccRCC is congruent with previous cohort of 220 metastatic ccRCC in RECORD3 study (4%).33 Co-occurrence of NF2 GA with VHL mutations in ccRCC cohort suggests that NF2 GA may be a secondary event in ccRCC, similarly to co-occurrence of TSC1 and TSC2 GA in VHL driven ccRCC.34 In the study of sarcomatoid ccRCC Malouf et al. presented one tumor with deleterious NF2 mutation in its sarcomatoid component only, suggesting that NF2 GA may represent a late event in ccRCC with sarcomatoid differentiation.35