Since angiogenesis in tumor tissues can be achieved, at least in part, by the recruitment of endothelial progenitor cells (EPCs) [101], the authors examined whether the presence of mammary carcinomas affects the development of CD45-CD117/c-Kit+Flk1/Vegfr2+ EPCs and whether CCL2 and CCR2 play a role in the process. The gene discussed is KDR; the disease is breast carcinoma.