WT1 and myocardial infarction: Only by using thymosin β4 (Tβ4) priming which had before been reported to initiate expression of embryonic developmental genes in the epicardium [105], a significant reactivation of Wt1 expression after myocardial infarction was achieved resulting in the appearance of some Wt1-positive cardiomyocytes in the border zone of the infarcted area.