We measured the production of three major proinflammatory cytokines, IL-21 (n = 114), IL-17 (n = 66) and IFN-γ (n = 116), by polychromatic flow cytometry in type 1 diabetes patients and healthy controls, matched as closely as possible for age, sex and time of sample preparation (Table 1). This evidence concerns the gene IL17A and type 1 diabetes mellitus.