Here, we report the generation of a novel transgenic (Tg) mouse that expresses Nano-lantern under the control of Flk1. Flk1-Nano-lantern BAC Tg mice recapitulate endogenous Flk1 expression including its expression in the dorsal aorta and micro blood vessels during development and tumour growth. The gene discussed is KDR; the disease is neoplasm.