PDGFD and breast cancer: In addition, PI3K-Akt signaling pathway and PPAR signaling pathway were confirmed that both play crucial roles in cell proliferation, invasion and metastasis [15], PI3K-Akt signaling pathway had been demonstrated to be activated in breast cancer, in the present study, 15 genes (IL6, FGF10, GNG11, KIT, PCK1, LAMB3, COL6A6, RELN, LAMC2, ANGPT1, TNN, PDGFD, EGF, PIK3R1, GHR) were down regulated in this pathway, and the result was validated using TCGA database.