The results indicated that high MDM2 expression was positively associated with weak TAB1 expression in the cytoplasm (P=0.001) and consistently, MDMX over-expression was also related to low expression of TAB1 in BC patients (P<0.001), which confirmed that the MDM2/MDMX inhibitor acted via the TAB1/TAK1/p38 MAPK pathway in the patient specimens examined. The gene discussed is MDM4; the disease is breast cancer.