For instance, T cells specific for T1D-associated self-antigens glutamic acid decarboxylase- (GAD) 65 and preproinsulin (PPI) are frequent in peripheral blood from both healthy individuals and patients, but are predominantly naïve in healthy and skewed towards a memory phenotype in the patients, indicating antigen-driven differentiation in an inflammatory setting in the latter (31–33). The gene discussed is INS; the disease is type 1 diabetes mellitus.