NKX2-2 (NK2 homeobox 2) is a member of a family of transcription factors that are involved in embryonic development and cell fate. NKX2-2 is crucial in the development of pancreatic islet cell differentiation and activates the ghrelin-promoter in these cells. NKX2-2 is expressed at the onset of pancreatic epithelium formation and becomes restricted to mature α-, β- and PP cells , and in NKX2-2-null mice embryos, all β-cells and most a-cells are replaced by ghrelin-positive cells. NKX2-2 is also thought to be involved in ventral neuronal patterning and floor plate development and commissural axon guidance.