As early as 1996, studies utilizing immunohistochemistry (IHC) demonstrated that MDM2-overexpressing breast cancer cells exhibited high expression levels of vascular endothelial growth factor (VEGF) and platelet-derived endothelial growth factor (PDGF), indicating the possible involvement of MDM2 in the angiogenesis process of malignancies [30]. This evidence concerns the gene MDM2 and breast cancer.