KDR and renal cell carcinoma: In 2011, a phase 2 trial by Jonasch et al. found that VEGFR2, pVEGFR2, and phosphorylated-to-total VEGFR2 ratios were statistically significantly higher in the RCC than in the HB samples (P = 0.001), and their study reported that 6 of 18 RCCs (33%) responded partially to sunitinib, vs. none of 21 HBs (P = 0.014) (17).