FGF4 and atrial fibrillation: Indeed, almost 70% of the secreted factors, including VEGF-C, EG-VEGF, PIGF, angiostatin, angiopoietin-2, FGF-4, FGF-7, acidic and basic FGFs, GM-CSF, MIP-1α, IGBP-1, thrombospondin -2, leptin, ADAMTS-1, DPPIV, TIMP-4 and MMP-8, were found at relatively higher concentrations in hDF-CM than in SS-AF-MSC-CM (p<0.05 for all).