Human Cardiotrophin-1 (CT-1) is a member of the leukemia inhibitory/ciliary neurotrophic factor/Oncostatin M/interleukin-6/interleukin-11 family of cytokines. Cardiotrophin-1 affects cells throμgh interaction with the gp 130 receptor subunit. Recombinant human Cardiotrophin-1 is a 22.5 kDa protein containing 200 amino acid residues.