Considerable information is known about the extracellular signals that drive pluripotent stem cells through a stepwise program to become cardiomyocytes. A paper by Ohtani et al. in this issue now links extrinsic signals to histone demethylation needed to form mesoderm, the first step in cardiogenesis.
Keywords: Editorials; Jmjd3; Nodal; Wnt; cardiac differentiation; demethylation; embryonic stem cells.