Our study found a significant association between MDM2 and HER2 overexpression subtype (p = 0.027) and is also in agreement with previous comprehensive analysis of the molecular subtype of breast cancer and MDM2 in which MDM2 expression were frequent in HER2 and luminal B subtypes but less common in luminal A and triple negative subtypes [12]. This evidence concerns the gene MDM2 and breast cancer.