Redefining the Target Again: Chemotherapeutics as Vascular Disrupting Agents?

In this issue of Cancer Cell, Shaked et al. (2008) provide novel mechanistic evidence that some chemotherapeutics induce circulating endothelial progenitor (CEP) mobilization with subsequent homing to tumor vasculature. Addition of an anti-VEGFR2 antibody increased antitumor activity only in combination with CEP-mobilizing chemotherapeutics. Here we discuss the implications of this work.