Moreover, the same group also found that hypoxia-preconditioned mouse cardiosphere-derived cell sheet remarkably improved left ventricular function with reduced fibrosis and enhanced angiogenesis via the activation of the PI3-kinase/Akt signaling pathway in a 2-month mouse MI model [63], and human cardiosphere-derived cell sheet after hypoxic preconditioning enhanced cellular function via activation of the PI3K/Akt/mTOR/HIF-1α pathway in an in vitro study [64]. Here, AKT1 is linked to myocardial infarction.