HPS1 encodes a component of the BLOC-3 (biogenesis of lysosome-related organelles complex-3), functioning as a guanine exchange factor (GEF) for RAB32 and RAB38 proteins to promote melanosome biogenesis and melanin production 1. The BLOC-3 complex regulates the conversion of these RAB proteins from inactive GDP-bound to active GTP-bound forms, essential for proper melanosome assembly and membrane localization 1. Mutations in HPS1 cause Hermansky-Pudlak syndrome type 1 (HPS-1), an autosomal recessive disorder characterized by oculocutaneous albinism and platelet storage pool disorder affecting all patients 2. HPS-1 patients additionally develop progressive fibrosing interstitial lung disease and bleeding diathesis, with pulmonary fibrosis representing the leading cause of mortality 3. HPS-1 accounts for approximately 1.6% of oculocutaneous albinism cases in Chinese populations 4. Disease modeling demonstrates that HPS1 mutations cause accumulation of extracellular matrix in lung tissue, suggesting early-onset intractable pulmonary fibrosis 5. Recent evidence identifies age-dependent emergence of inflammatory SAA3+ fibroblasts in HPS1 lungs, with increased IL-1R1 expression indicating complex epithelial-fibroblast interactions driving fibrotic progression 6. Currently, lung transplantation remains the only definitive therapeutic option for HPS-1 pulmonary fibrosis 7.