The term 'ISLET of Langerhans' refers to small clusters of cells found in the pancreas. These cells are responsible for producing hormones such as insulin, glucagon, and somatostatin. The ISLETS are named after the German pathologist Paul Langerhans, who first described them in 1869. ISLETS can also be referred to as 'ISLETS of Langerhans' or simply 'ISLETS'. The term 'ISLETS' is used to refer to a group of cells, while 'ISLET' is used to refer to a single cell.