Non-cardiomyocyte fate of epicardial cells after TB4 injection. (A) FACS isolation of GFP+ EPDCs from Wt1CreERT2/+;Rosa26mTmG/+ hearts treated by LAD ligation followed by TB4 injection. (B) Quantitative RT-PCR showed highly purified EPDCs after FACS isolation (n=3). (C) Immunostaining of primary EPDCs isolated from infarcted, TB4-treated hearts showed co-expression of markers of epicardial cells (WT1, TBX18) and smooth muscle or myofibroblast cells (CNN1, αSMA), but not cardiomyocytes (TNNT2, ACTN2). (D) Immunostaining of primary isolated EPDCs from infarcted, PBS-treated hearts. White bar=50 μm.