MYZAP (myocardial zonula adherens protein) is a component of cardiac intercalated discs that functions as a scaffolding protein at cell junctions 1. MYZAP localizes to the cytoplasmic side of the plasma membrane and plays a role in intracellular signal transduction, potentially via Rho-related GTP-binding proteins and subsequent SRF activation [UniProt]. In the central nervous system, MYZAP may participate in glutaminergic signaling through interaction with the NMDA receptor subunit GRIN1, colocalizing with internexin-alpha to form a neuroprotective pathway 2. MYZAP is present in cardiac nodes and contributes to mechanical junction integrity alongside desmoplakins and other adherens junction proteins 3. Clinically, MYZAP is associated with dilated cardiomyopathy (DCM), with homozygous truncating variants in the GCOM1/MYZAP locus causing fully penetrant recessive cardiomyopathy characterized by heart failure and atrial arrhythmias 4. A missense MYZAP variant was identified in genome-wide association studies of atrial fibrillation (OR=1.38), emphasizing the link between cardiac mechanical and electrical dysfunction 1. Additionally, MYZAP serves as an autoantigen in endemic pemphigus foliaceus, where patient autoantibodies target MYZAP at vascular and cardiac cell junctions, potentially contributing to arrhythmias and vascular dysfunction 35.