GAD1 and type 1 diabetes mellitus: In contrast, individuals with newly diagnosed type 1 diabetes harboured significantly higher frequencies of CD8+ T cells specific for epitopes derived from GAD (p < 0.05), proinsulin (p < 0.05), islet-specific glucose-6-phosphatase catalytic subunit-related protein (p < 0.05) and insulin (p < 0.05) compared with healthy donors (Fig. 2b–e), and individuals with long-standing type 1 diabetes harboured significantly higher frequencies of CD8+ T cells specific for the epitopes derived from GAD (p < 0.05) and insulin (p < 0.05) compared with healthy donors (Fig. 2b,e).