Zhu et al. showed that the overexpression of cyclin D2 in human iPSC-CMs increased graft size and improved myocardial recovery in a mouse model of MI by increasing the proliferation of transplanted cells, which played a significant role in myocardial remyelination and ventricular function recovery (Zhu et al., 2018). Here, CCND2 is linked to myocardial infarction.