FLT1 and neoplasm: Initially, expression of Flt-1 and KDR was believed to be restricted to the vascular endothelium, but to date these receptors have also been detected in several types of nonendothelial cells including breast cancer cells, suggesting an autocrine effect of VEGF-A on tumour cells (De Jong et al, 1998a; Kranz et al, 1999).