HSBP1 (heat shock factor binding protein 1) is a small 76-amino acid nuclear protein that serves as a negative regulator of the heat shock response through its interaction with heat shock factor 1 (HSF1) 1. The protein contains hydrophobic repeats that interact with HSF1's trimerization domain, inhibiting HSF1 DNA-binding activity and suppressing heat shock protein 70 (HSP70) transcription 1. Beyond stress response regulation, HSBP1 functions in cellular assembly processes by promoting WASH complex formation at centrosomes, which is critical for endosomal trafficking and focal adhesion development 2. HSBP1 demonstrates significant disease relevance across multiple pathologies. In cancer, elevated HSBP1 expression promotes stem cell-like properties in ovarian cancer cells and correlates with poor prognosis 3. In oral squamous cell carcinoma, HSBP1 overexpression enhances radiotherapy resistance and increases stem cell markers 4. The protein also mediates bacterial-induced fibrosis in hypertrophic scars through autophagy activation 5. Clinically, HSBP1 expression levels serve as prognostic markers in various cancers and may represent a therapeutic target, particularly given its role in treatment resistance and tissue remodeling processes.