To confirm that highly secreted factors from SS-AF-MSCs, such as IL-8, PDGF-AB/BB and MMP9, function in regulating in UCB ECFC derived cell motility, an in vitro transwell migration assay was performed using neutralizing Abs for the IL-8 and PDGF-AB/BB cytokines and an inhibitor for MMP-9. Here, CXCL8 is linked to atrial fibrillation.