CADPS (calcium-dependent secretion activator) is a multi-domain protein that regulates Ca2+-dependent exocytosis of neurotransmitter and neuropeptide-containing vesicles 1. CADPS functions as a PtdIns(4,5)P2-binding protein that acts at the prefusion step following ATP-dependent priming and participates in dense-core vesicle membrane fusion 2. The protein contains a C2 domain involved in calcium and phospholipid interactions and shows tissue-specific expression, being restricted to neural and endocrine tissues 1. Functionally, CADPS acts upstream of fusion in the biogenesis or maintenance of mature secretory vesicles and regulates catecholamine loading of dense-core vesicles 1. Disease relevance includes association with bipolar disorder, where functional mutations increase stress sensitivity and lead to manic-like behaviors in mouse models 3. CADPS variants have also been identified in autism spectrum disorders, particularly in high-functioning autism cases 45. Additionally, reduced CADPS expression correlates with poor prognosis in cholangiocarcinoma, where it functions as a tumor suppressor through ERK and p38 MAPK signaling pathways 6. The protein's role in vesicle exocytosis makes it clinically relevant for neurological and psychiatric disorders involving synaptic dysfunction.