SNX19 (sorting nexin 19) is a multifunctional protein involved in intracellular vesicle trafficking and membrane dynamics. The protein contains a PX domain that specifically binds phosphatidylinositol 3-phosphate (PtdIns(3P)), enabling its localization to early endosomal membranes 1. SNX19 plays important roles in pancreatic beta-cell function, where it interacts with IA-2 (islet antigen-2) and may regulate insulin secretion by maintaining insulin-containing dense core vesicles 2. Beyond metabolic functions, SNX19 demonstrates significant involvement in dopamine D1 receptor trafficking through interactions with lipid raft components caveolin-1 and flotillin-1, containing specific binding motifs for these proteins that are essential for proper receptor endocytosis and signaling 3. The protein also functions as a chondrogenic factor, promoting cartilage differentiation and being expressed in limb cartilage during development 4. Notably, SNX19 has emerged as a schizophrenia risk gene, with disease-associated genetic variants influencing multiple transcript classes, particularly those lacking the characteristic nexin C-terminal domain 5. In human brain tissue, SNX19 is preferentially expressed in glutamatergic neurons in the dorsolateral prefrontal cortex, suggesting its potential role in schizophrenia pathophysiology through disruption of glutamatergic function 6.