MSTN and myocardial infarction: Given the controversy of the effects of high circulating GDF11 on cardiac structure and function, we aimed to probe the effects of high systemic GDF11 on myocardial I/R injury by harnessing an array of methods, ranging from an established in vivo I/R model,45 omics-guided in vitro approaches12,46,47 to liquid chromatography-tandem mass spectrometry (LC-MS/MS)–based investigations of circulating GDF11 and MSTN levels in prospectively recruited patients with MI.31,48–50