Carriage of a common intronic MTNR1B variant, rs10830963, has shown strong association with high fasting plasma glucose (FPG) levels [4, 8, 9], low beta cell glucose sensitivity [10], early phase insulin secretion [8, 10, 11], and a significantly greater prevalence of prediabetes [9] and type 2 diabetes than observed in non-carriers [8, 9, 12]. Here, INS is linked to type 2 diabetes mellitus.