The microarray analysis also indicated an upregulation of three tumor promoter genes prostaglandin-endoperoxide synthase 2 (PTGS2), serpin peptidase inhibitor, clade E, member 2 (SERPINE2), and macrophage migration inhibitory factor (MIF) in both human and rat UCMSC when they were co-cultured with breast carcinoma cells. Here, PTGS2 is linked to breast carcinoma.