CSEN, also known as calsenilin and KCNIP3, is a member of the family of voltage-gated potassium (Kv) channel-interacting proteins, which belong to the recoverin branch of the EF-hand superfamily. Members of this family are integral subunit components of native Kv4 channel complexes that may regulate A-type currents, and hence neuronal excitability, in response to changes in intracellular calcium. CSEN also functions as a calcium-regulated transcriptional repressor, and interacts with presenilins. CSEN binds to the DRE element of genes including PDYN and FOS.