GJA1 and myocardial infarction: Previous studies have shown that a reduction in Cx43 expression in heterozygous Cx43+/- mice attenuates myocardial infarct size, as assessed by histological Masson’s trichrome staining of ventricular slices, both during the healing phase (8 days after surgery) and in fully healed infarcts (10 weeks after occlusion), as compared with Cx43+/+ wild-type animals [13].