SDF2 (stromal cell-derived factor 2) is an endoplasmic reticulum (ER) chaperone protein that plays critical roles in protein folding and cellular homeostasis 1. The protein localizes to the ER and functions as a component of chaperone complexes, particularly with DNAJB11 and SDF2L1, to facilitate proper protein processing 23. SDF2 is essential for the processing of Polycystin-1, with loss of SDF2 and SDF2L1 impairing PC1 processing and potentially contributing to polycystic kidney disease 2. In the cardiovascular system, SDF2 serves as a critical component of the Hsp90-eNOS complex, regulating endothelial nitric oxide synthase activation and nitric oxide synthesis 4. The protein is involved in ER stress responses and the unfolded protein response pathway 51. Clinically, SDF2 expression is elevated in various cancers including glioma and gastric cancer, where it promotes tumor progression through mechanisms involving ER-associated degradation pathways and copper homeostasis 67. High SDF2 expression correlates with poor prognosis in gastric cancer patients, suggesting its potential as a therapeutic target 7.