STAT3/Pim-1 signaling pathway plays a crucial role in endothelial differentiation of cardiac resident Sca-1+ cells both in vitro and in vivo

► IL-6 family cytokines induce endothelial differentiation of cardiac Sca-1+ cells. ► In this process, the expression of Pim-1 is upregulated through STAT3 pathway. ► Pim-1 activity is essential for their differentiation both in vitro and in vivo.