Thus, pre-treated MSCs with insulin-like growth factor 1 (IGF-1) for 48 h markedly increased the CXCR4 expression in vitro, and a greater number of MSCs treated with IGF-1 engrafted and survived in the peri-infarcted area when the cells were transplanted in a rat model of myocardial infarction (Guo et al., 2008). Here, IGF1 is linked to myocardial infarction.