GJA1 and cardiac arrhythmia: The S282 phosphorylation site on Cx43 regulates myocardial survival (inhibiting apoptosis via mitochondrial pathway when phosphorylated, activating pro-death signaling when dephosphorylated) and electrical conduction; S282-mutant mice exhibit arrhythmias and increased apoptosis, highlighting its homeostatic role (Yang et al., 2019) S282-mutant mice show severe ventricular arrhythmias and increased myocardial apoptosis, highlighting S282 phosphorylation’s critical role in cardiomyocyte homeostasis.