Insulin the simplest unicellular eukaryotes. Apart from animals, insulin-like proteins are also known to exist in the Fungi and Protista kingdoms. Insulin is produced by beta cells of the pancreatic islets in most vertebrates and by the Brockmann body in some teleost fish. Cone snails "Conus geographus" and "Conus tulipa", venomous sea snails that hunt small fish, use modified forms of insulin in their venom cocktails. The insulin toxin, closer in structure to fishes' than to snails' native insulin, slows down the prey fishes by lowering their blood glucose levels. The preproinsulin precursor of insulin is encoded by the "INS" gene.
Insulin (medication) attempt to mimic real beta cell insulin (as with insulin lispro, insulin aspart, and insulin glulisine), or steadily absorbed after injection instead of having a 'peak' followed by a more or less rapid decline in insulin action (as with insulin detemir and insulin glargine), all while retaining insulin's glucose-lowering action in the human body. However, a number of meta-analyses, including those done by the Cochrane Collaboration in 2005, Germany's Institute for Quality and Cost Effectiveness in the Health Care Sector [IQWiG] released in 2007, and the Canadian Agency for Drugs and Technology in Health (CADTH) also released in 2007 have