KDR and neoplasm: Vascular endothelial growth factor receptors are in most cases specifically expressed on vascular endothelial cells, but certain tumour cells also express VEGFR2 (Masood et al, 1997; Dias et al, 2000; Masood et al, 2001; Podar et al, 2001; Strizzi et al, 2001; Jackson et al, 2002; Nakopoulou et al, 2002).