CLCF1, also known as cardiotrophin-like cytokine factor 1, belongs to the interleukin 6 family of cytokines, which are involved in cell signaling through phosphorylation of gp130. CLCF1 has a sequence of 225-amino acids with a 27-aa signal peptide, a molecular mass of 22 kDa in mature form, and the highest homology to cardiotrophin-1 and ciliary neurotrophic factor. CLCF1 can be actively secreted from cells by forming a complex with soluble type I CRLF1 or soluble CNTFR. Defects in CLCF1 cause cold-induced sweating syndrome 2 (CISS2). This syndrome is characterized by a profuse sweating after exposure to cold as well as congenital physical abnormalities of the head and spine. Synonyms: Cardiotrophin-like cytokine factor 1, BSF-3, BSF3, CISS2, CLC, NNT-1, NNT1, NR6. NCBI no.: NP_037378