IL2RG and nonpapillary renal cell carcinoma: To assess tumorigenicity, 1 million VHLmut cells were injected under the renal capsule of five NOD/SCID/IL2Rγ−/− mice and 2 out of 4 VHLmut cultures consistently generated tumor xenografts with ccRCC histology within 10 weeks (Additional file 10: Figure S4).