PEX19 is a cytosolic chaperone and import receptor essential for early peroxisomal biogenesis 1. It binds and stabilizes newly synthesized peroxisomal membrane proteins (PMPs) through interactions with their hydrophobic domains, then targets them to the peroxisome by binding the integral membrane protein PEX3 2. This PEX3-PEX19 interaction occurs primarily at the peroxisomal membrane and is critical for import-competent peroxisome formation 2. Beyond peroxisomal targeting, PEX19 facilitates sorting of membrane proteins to other organelles including endoplasmic reticulum, lipid droplets, and mitochondria 3. Additionally, PEX19 regulates pexophagy by recruiting the ubiquitin ligase MARCH5 to peroxisomes 4, and mediates antiviral responses by suppressing influenza A virus replication through peroxisomal MAVS-mediated interferon signaling 1. Pathologically, mutations in PEX19 cause peroxisome biogenesis disorder complementation group 14, with rare nonsense mutations identified in Zellweger spectrum disorder, presenting with neurological dysfunction, hypotonia, and craniofacial abnormalities 5. Clinically, inhibiting the PEX3-PEX19 interaction combined with other targeted approaches shows promise in melanoma therapy resistance models 6.