1,2-Dipalmitoyl-sn-glycero-3-phosphate monosodium salt (Phosphatidic Acid, DPPA) is a bioactive phospholipid. Dipalmitoylphosphatidic acid (DPPA) is a minor phospholipid metabolite that is involved in lipid biosynthesis. DPPA has two palmitic acid moieties instead of AA and can convert to lyso-PA to increase Bcl-2 expression in Hela cells but not in B lymphoma cells. DPPA significantly inhibited tumor growth, cell proliferation and tumor angiogenesis. Furthermore, DPPA strongly arrested the G2/M transition and further inhibited cell cycle progression in MDA-MB-231 cells. cyclin B1 (CCNB1) was the DPPA target that regulated cellular proliferation in human TNBC. DPPA, as an anti-cancer drug, inhibited the expression of CCNB1 to arrest the G2/M transition in human TNBC.