BFSP1 (beaded filament structural protein 1) is a lens-specific intermediate filament protein essential for ocular function and increasingly recognized in cancer biology. In the eye, BFSP1 forms beaded filament complexes with BFSP2 and CRYAA to establish correct lens intermediate filament architecture, critical for maintaining lens transparency and optical properties 1. BFSP1 also regulates calcium-dependent water permeability of lens aqueous channels 2. Mutations in BFSP1 cause congenital and age-related cataracts through reduced protein expression and increased cellular apoptosis 34; multiple pathogenic variants including frameshift and missense mutations have been identified in cataract families 5. Beyond ocular function, BFSP1 has recently emerged as a cancer-associated protein. M6A methylation-mediated stabilization of BFSP1 promotes hepatocellular carcinoma progression by enhancing aerobic glycolysis through direct interaction with tropomodulin 4 6. BFSP1 overexpression correlates with poor prognosis, reduced survival, and increased tumor migration in liver cancer, with functional knockdown significantly inhibiting metastatic potential 7. Additionally, BFSP1 was identified as a differentially expressed gene linked to oxidative stress in kidney stone pathology 8, suggesting broader pathophysiological roles beyond the lens.