Cardiotrophin 1 (CT-1) is a proinflammatory cytokine that belongs to the IL-6 cytokine family, which includes IL-6, IL-11, IL-27, leukemia inhibitory factor (LIF), oncostatin M (OSM), cardiotrophin-like cytokine (CLC), ciliary neurotrophic factor (CNTF) , and neuropoietin (NP). CT-1 is a secreted protein; nevertheless it does not have a signal peptide. It is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, rat, and human. CT-1 plays a major role in cardiac, neurological, and liver biology. Also, it is capable of increasing osteoblast activity and mineralization in both?in vitro and in vivo studies. In addition, in vitro and in vivo experiments have shown that CT-1 improves beta cell function and survival, and protects mice against streptozotocin-induced diabetes. Moreover, aldosterone induces CT-1 expression in HL-1 adult cardiomyocytes. In vivo, aldosterone increases the myocardial expression of CT-1 in C57BJ6 wild-type mice but not CT-1-null mice.