VHL inactivation is the most established cause of ccRCC, but there are several other factors involved in pathogenesis of tumor type exemplified by mutations in KNG1 and MT1A genes [7], as well as PI3K/AKT/mTOR signaling pathway factors (MTOR, PTEN, PIK3CA) [8]. This evidence concerns the gene VHL and nonpapillary renal cell carcinoma.