Apelin Enhances Directed Cardiac Differentiation of Mouse and Human Embryonic Stem Cells. - Wang, I-Ning E.; Xiang Wang; Xiaohu Ge; Anderson, Joshua; Ho, Michael; Ashley, Euan; Jianwei Liu; Butte, Manish J.; Yazawa, Masayuki; Dolmetsch, Ricardo E.; Quertermous, Thomas; Yang, Phillip C. (PLoS ONE, 2012)