Overexpression of circNfix inhibits cardiomyocytes proliferation in vitro and in vivo, whereas circNfix downregulation promotes cardiomyocytes proliferation and decreases cardiomyocytes apoptosis after MI, attenuating cardiac dysfunction by suppressing Y-box binding protein 1 (Ybx1) ubiquitin-dependent degradation and increasing miR-214 activity (Huang et al., 2019). Here, YBX1 is linked to myocardial infarction.