Sphingosine‐1‐Phosphate Receptor 1 Regulates Cardiac Function by Modulating Ca <sup>2+</sup> Sensitivity and Na <sup>+</sup> /H <sup>+</sup> Exchange and Mediates Protection by Ischemic PreconditioningPetra Keul, Bodo Levkau, Marek Máťuš et al.|Journal of the American Heart Association|2016Cited by 64