This SNP on chromosome 16q23.1 has been identified as a risk factor for type 1 diabetes [14] and as a protective factor for type 2 diabetes [15], and increase gene expression of CTRB1/2 in islets and pancreata and enzyme activity in stool, implicating a key role of the enteroendocrine system. The gene discussed is CTRB1; the disease is type 2 diabetes mellitus.