KCNN1 encodes SK1, a small-conductance calcium-activated potassium channel that mediates voltage-independent potassium transport across cell membranes through constitutive interaction with calmodulin 1. The channel exhibits characteristic properties including voltage-independent activation, calcium concentration-dependent activation, and approximately 3 picosiemens single-channel conductance 1. KCNN1 functions primarily in regulating neuronal excitability by contributing to afterhyperpolarization currents in sensory neurons, with reduced expression leading to increased neuronal excitability 1. The gene shows complex transcription patterns with multiple splice variants that may fine-tune channel function 2. Beyond neuronal function, KCNN1 demonstrates tissue-specific expression in cardiac myocytes where it affects action potential duration and arrhythmic tendency 3, and in reproductive tissues including the myometrium 4. Disease relevance includes neuropathic pain, where KCNN1 downregulation contributes to pain hypersensitivity 1, and cancer, where it promotes breast cancer proliferation and metastasis through interaction with ERLIN2 and Cyclin B1 5. In Ewing sarcoma, KCNN1 overexpression driven by EWS::FLI1 fusion proteins regulates cell proliferation and calcium signaling 6.