TMED4 (transmembrane p24 trafficking protein 4) is a transmembrane protein involved in vesicular transport within the early secretory pathway. As a member of the p24 protein family, TMED4 cycles between the endoplasmic reticulum (ER) and Golgi compartments 1, playing a critical role in COPII-coated ER-to-Golgi vesicle-mediated transport and maintenance of Golgi apparatus organization. During germ cell differentiation, TMED4 (p25) continues to mark Golgi identity as the organelle migrates during acrosome formation, indicating its importance in dynamic cellular reorganization 2. Clinically, TMED4 dysfunction has been associated with dilated cardiomyopathy (DCM), a leading cause of heart failure. A rare loss-of-function single nucleotide variant in TMED4 was identified in Pakistani DCM patients, suggesting genetic contributions to this disease 3. TMED4 and related p24 family proteins contain GOLD domains characteristic of ER-Golgi trafficking proteins and appear to participate in stress responses, potentially regulating heat-shock response and apoptosis through mechanisms involving oxidative stress and ER stress pathways 1. These findings indicate TMED4 importance extends beyond routine protein trafficking to include roles in cellular stress adaptation and cardiac function.