HSP90AB1 is a molecular chaperone protein that functions as a key regulator of cellular stress responses and protein homeostasis. Mechanistically, HSP90AB1 operates through ATP-dependent binding interactions, serving as a component of the HSP90-CDC37 chaperone complex 1 and regulating translation of specific mRNAs containing TOP-like motifs downstream of mTORC1 signaling 1. The protein prevents pathological protein misfolding and aggregation, with differential distribution across hippocampal subfields during Alzheimer's disease progression 2. In disease contexts, HSP90AB1 has multiple clinical relevances. In cardiac pathology, HSP90AB1 SUMOylation mediates myocardial fibrosis through STAT3 activation and fibronectin secretion; SENP1-mediated deSUMOylation of HSP90AB1 prevents adverse ventricular remodeling post-infarction 3. HSP90AB1 serves as a pan-EVP (extracellular vesicle/particle) biomarker for cancer detection with 95% sensitivity and 90% specificity in plasma-derived samples 4, and is implicated in osteosarcoma metastasis as a hub gene 5. Additionally, HSP90AB1 promotes pathogenic viral replication by protecting coronavirus nucleocapsid proteins from proteasomal degradation 6 and is associated with immune microenvironment changes in Alzheimer's disease 7. In kidney disease, HSP90AB1 mediates podocyte injury through B7-1-LRP5-β-catenin signaling 8.