Flow cytometry (Figure 6B) showed that 40 min rhIL-15 treatment did not induce STAT5 phosphorylation in γc- or JAK3-transfected RCC while rhIL-15 activated STAT5 phosphorylation in co-transfected cells (γc/JAK3-RCC7), suggesting that expression of both molecules is necessary to reestablish the STAT5 signal transduction pathway in RCC. This evidence concerns the gene JAK3 and renal cell carcinoma.