PROM1 and nonpapillary renal cell carcinoma: The percentage of NK‐CD133+cells that respond by colocalization of TNFR2 and pSTAT3Ser727 is significantly less and activation of the kinase cascade appears to predominantly involve Akt and mTOR, with less activation of VEGFR2 and PI‐3K than in ccRCC‐CD133+CSCs (Figure 2).