Evaluation of the effects of sunitinib on EC survival in coculture with primary RCC. (A) CAM5.2 and PAX-2 staining of 786-O and indicated primary RCC cells; ×200 magnification. (B) Tumor-induced EC survival correlates with secreted VEGF levels; R = 0.57 and P = 0.0028. (C) EC survival in cocultures. Data are means ± SEM. n = 13 for TG206, n = 3 for TG250, n = 4 for TG158, n = 3 for T285, n = 3 for T283, n = 4 for TG185, n = 10 for TG127, n = 4 for T258, n = 6 for T241, n = 8 for TG121, n = 4 for PF22, and n = 6 for T239. *, P < 0.05; **, P < 0.01, ***, P < 0.001.