PLXDC1 and neoplasm: PLXDC1 (also called tumor endothelial marker 7) was discovered as one of the genes enriched in many types of human tumor endothelial cells (St Croix et al., 2000; Schwarze et al., 2005; Beaty et al., 2007; Lu et al., 2007; van Beijnum et al., 2009).