RTN1 (reticulon 1) is an endoplasmic reticulum (ER)-resident protein with context-dependent roles in cellular homeostasis and disease. In the central nervous system, RTN1 modulates amyloid-beta pathology by inhibiting BACE1 activity 1, though RTN3 appears more prominent in Alzheimer's disease pathogenesis. However, RTN1 demonstrates dual functionality in metabolic and renal disease contexts. In diabetic kidney disease, RTN1A mediates tubular epithelial cell (TEC) injury through dysregulation of ER-mitochondrial contacts, disrupting the hexokinase-1/VDAC1 interaction and triggering apoptotic and inflammasome pathways 2. RTN1A is also a critical mediator of diabetes-accelerated acute kidney injury-to-chr14 kidney disease transition 3. Beyond renal disease, RTN1 associates with senescence-related pathology shared between polycystic ovary syndrome and type 2 diabetes 4, and serves as a potential tumor suppressor in lung adenocarcinoma linked to immune infiltration patterns 5. RTN1 interacts with multiple proteins including MANF in the ER lumen 6. These findings suggest RTN1 functions as a multifaceted regulator of ER-mitochondrial crosstalk and protein processing with tissue-specific pathophysiological consequences, positioning RTN1 inhibition as a potential therapeutic strategy for diabetic complications.