Recent research suggests that genetic variations in the ONECUT1 gene contribute to various forms of diabetes by impairing the function of insulin-producing pancreatic β-cells; Philippi et al. (2021) presented an exemplary study on this subject, wherein they observed rare variants within the ONECUT1 gene in individuals with monogenic diabetes (recessive and dominant) and multifactorial type 2 diabetes (T2D). Here, ONECUT1 is linked to diabetes mellitus.