In contrast, PLXDC2, but not PLXDC1, was found as one of the genes that increase in expression during cellular senescence (Schwarze et al., 2005), as one of the E2F1 target genes repressed by serum (Hallstrom et al., 2008), as a gene negatively correlated with malignant cell transformation in tumors and its disturbance increases tumor volume (McMurray et al., 2008), and as a candidate axon guidance molecule (Leighton et al., 2001). This evidence concerns the gene E2F1 and neoplasm.