Su1498 (Tyrphostin SU 1498) is a selective inhibitor of the receptor tyrosine kinase VEGF receptor 2 (VEGFR2, aka FLK1; IC50 = 700 nM), having negligible activity at several other serine/threonine and tyrosine kinases.1, 2 It effectively blocks signaling through VEGFR2 both in vitro and in vivo.1, 3 SU 1498 is used to study the role of VEGFR2 signaling in diverse processes, including angiogenesis, tumor growth, neural progenitor cell survival, and neuroregeneration.