GLB1 encodes lysosomal β-galactosidase, a critical enzyme involved in glycoconjugate degradation and cellular homeostasis. The enzyme catalyzes the hydrolysis of β-galactoside linkages in various substrates including GM1-ganglioside, glycoproteins, and keratan sulfate 1. GLB1 serves as the basis for senescence-associated β-galactosidase (SA-β-gal) activity, a widely used biomarker for cellular senescence detectable at pH 6.0, which represents increased expression of the lysosomal enzyme during senescence 2. The protein functions within lysosomes to maintain cellular homeostasis through substrate degradation, and its dysregulation is implicated in various pathological processes. Mutations in GLB1 cause GM1-gangliosidosis, a progressive lysosomal storage disorder characterized by accumulation of GM1-ganglioside and other galactose-containing glycoconjugates in neuronal tissue, leading to severe neurocognitive decline 1. The disease is classified into three forms based on age of onset, with Type I being the most severe infantile form. GLB1 activity is also linked to autophagy regulation and mitochondrial quality control, as demonstrated in studies of cellular senescence where SA-β-gal expression correlates with autophagic processes and cellular stress responses 34. Current therapeutic approaches include gene therapy trials targeting GLB1 restoration.