Contrary to the Cx43 inhibition, Roell et al. (2018) demonstrated that Cx43 overexpression of MFs in the border zone of mouse myocardial infarction increases conduction velocity and reduces the likelihood of arrhythmias possibly via improvement of inter-MF gap-junctional connection (Roell et al., 2018). The gene discussed is GJA1; the disease is cardiac arrhythmia.