We have shown previously that overexpression of EphB4 in tumour cells is tightly regulated by known transforming agents such as EGFR (Masood et al, 2006) and HER-2/neu (Kumar et al, 2006), and inhibited by tumour suppressors such as p53 (Xia et al, 2006) and PTEN (Xia et al, 2005). This evidence concerns the gene TP53 and neoplasm.