MAPK8 and breast cancer: To explore the role of phosphatidylinositol 3-kinase (PI3K)/protein kinase B9 (AKT) and mitogen-activated protein kinase (MAPK) pathways in the inhibitory effects PD on cell proliferation, breast cancer cells MDA-MB-231 and MCF-7 were pre-treated with 10μM Specific PI3K inhibitor wortmannin, ERK1/2 inhibitor PD98059, P38 inhibitor SB203580, and JNK inhibitor SP600125 for 1h.