Okamoto et al. have shown that bone marrow suppression by anti-c-Kit treatment induces a delay in tumor angiogenesis due to the inhibition of angiogenic sprouting in colon tumors and that c-Kit blockade suppresses tumor growth of subcutaneously implanted prostate carcinomas (PC3) by inhibition of tumor angiogenesis regulated by HCs [7]. The gene discussed is KIT; the disease is prostate carcinoma.