We have identified type 1 diabetes (T1D)-associated differential DNA methylated variable positions (T1D-MVPs) in CD14+ from peripheral blood mononuclear cells (PBMCs) from monozygotic (MZ) twins discordant for T1D (Rakyan V et al.; Plos Genetics 2011). We aim to determine the role of T1D-associated MVPs in the mechanisms that underpin immune dysfunction in T1D. We have therefore studied whether the same disease signature is detectable in T1D tissue compared with normal tissues relevant to the disease, namely: pancreatic lymph nodes (site of self-reactive T cells priming) compared with the spleen (as control). In addition we are examining the methylation state of T1D-MVPs in selected cells from human thymus and we intend to make these cells available to nPOD in due course.