ARG1 and myocardial ischemia: The significant decrease in the iNOS to Arg1 ratio in BMDMs co-cultured with MSCs indicates that MSCs may catalyze cardiac repair by pushing the macrophage phenotype towards M2.[43] Additionally, Zhao et al uncovered the pivotal role of MSC-derived exosomes (MSC-Exos) in ameliorating myocardial ischemia–reperfusion injury.