TKT and myocardial infarction: For example, the delivery and expression of the human TK gene in the cardiac tissue markedly mitigated heart enlargement and dysfunction in rats exposed to pressure overload.7 Furthermore, Gao et al8 showed that human TK-transfected mesenchymal stem cells provided cardioprotection against myocardial infarction-induced hypertrophy and fibrosis mainly through the ability of TK to diminish ischemia-triggered cardiomyocyte apoptosis, leukocytes recruitment, and proinflammatory mediators’ expression.