SNX12 (sorting nexin 12) is a member of the PX domain-containing sorting nexin family that plays essential roles in endosomal protein trafficking and membrane transport. SNX12 is primarily localized to early endosomes, where its localization depends on binding to 3-phosphoinositides 1. The protein functions in multiple stages of intracellular trafficking, particularly in the early phase of cargo transport and receptor recycling upstream of other retromer components 2. SNX12 plays a key role in intraluminal vesicle formation and maturation of early endosomes into late endosomes, thereby regulating selective endocytic transport for degradation 2. The protein shares redundant functions with SNX3 in multivesicular endosome biogenesis, and overexpression prevents multivesicular endosome detachment from early endosomes, inhibiting the degradative pathway 1. SNX12 has clinical relevance in neurodegeneration, as it interacts with BACE1 and regulates β-amyloid production, with reduced SNX12 levels observed in Alzheimer's disease patient brains 3. Additionally, SNX12 serves as a neuroprotective factor, as demonstrated by its role in mitigating isoflurane-induced neurotoxicity in diabetic rats 4.