KDR and coronary artery disorder: While VEGFR2 signaling is extremely complex, and more than half a dozen pathways are recognized,19 a possible link between malfunctioning VEGFR2 phosphorylation and CHD comes from the knowledge that Tyr1175 phosphorylation is important in activation of the PLCΥ-ERK1/2 pathway17,18 and that disturbed ERK1/2 signaling contributes to cardiac defects that comprise TOF in vivo.32,33 Future studies are needed to address the exact downstream pathways affected by decreased VEGFR2 Tyr1175 phosphorylation.