DUSP22 and hyperinsulinemic hypoglycemia, familial, 4: Interestingly, we could also detect epigenetic alterations in response to seipin deficiency, including DNA methylation changes at the promoter of DUSP22. Nevertheless, our study only focused on CGL type 2; therefore, in future studies, it is important to check whether the observed epigenetic changes, as well as the epigenetic age acceleration, are specific to CGL type 2 or if it also occurs in CGL types 1, 3 and 4.