9 RTKs (EGFR1–3, Insulin R, PDGFRβ, VEGFR1, VEGFR2, HGFR, and M-CSFR) were found to be phosphorylated in the ccRCC samples (Fig. 2 and Fig. 3). This evidence concerns the gene FLT1 and nonpapillary renal cell carcinoma.