BST1 (bone marrow stromal cell antigen 1) is a bifunctional NAD+-metabolizing enzyme that catalyzes both synthesis of cyclic ADP-ribose (cADPR) from NAD+ and its hydrolysis to ADP-ribose 1. As a critical second messenger, cADPR regulates intracellular calcium mobilization from endoplasmic stores, modulating calcium-dependent signaling and cellular responses 1. BST1 also functions as a glycohydrolase and base-exchange enzyme in nicotinamide riboside (NR) metabolism, hydrolyzing NR to nicotinamide and facilitating NAD+ generation through multiple pathways 2. Clinically, BST1 variants show significant disease associations. A novel BST1 locus (rs4698412) was identified as a genome-wide significant determinant of Parkinson's disease age-of-onset 3, while rare loss-of-function BST1 variants associate with isolated REM sleep behavior disorder 4. Evidence suggests BST1 implication in both autism spectrum disorders and parkinsonism 5. Additionally, BST1 emerged as a promising biomarker for chemoimmunotherapy response in stage III non-small cell lung cancer 6, and bioinformatics analyses identified BST1 as a therapeutic target linked to neutrophil extracellular traps in acute liver failure pathogenesis 7. These findings position BST1 as a multifunctional enzyme with therapeutic potential across neurological, oncological, and inflammatory diseases.