Cardiotrophin-1 is a pleiotrophic cytokine and is a member of the IL-6 cytokine family that also includes IL6, IL11, LIF, OSM, CLC and IL31.Full length human CT-1 shares a 79% amino acid sequence identity with murinic CT-1 and both lack a canonical signal sequence. Cardiotrophin-1 interacts with the leukemia inhibitory factor receptor (LIFR) heterodimer and the glycoprotein 130 subunit (gp130) and has the ability to induce cardiac myocyte hypertrophy. It is highly expressed in various skeletal muscles and cardiac tissue, as well as the colon, ovary and prostate, liver, and pancreas, while lower expression levels are found in the lungs, kidney, pancreas, testis, and small intestine.