To test whether age influenced patterns of metabolic progression prior to the onset of stage 3 type 1 diabetes, we utilised a mathematical model that reconstructs insulin sensitivity and endogenous insulin secretion from C-peptide kinetics [20] and resolves three main modes of beta cell function, namely the glucose dose–response, early insulin secretion, and potentiation [13–17]. The gene discussed is INS; the disease is type 1 diabetes mellitus.