Thus, in this study we tested the hypothesis that type 2 diabetes-predisposing TCF7L2 SNPs are associated with a higher percentage of residual insulin-containing cells (ICI%) in pancreases of donors with type 1 diabetes by using available genomic data and tissue samples from the Network for Pancreatic Organ donors with Diabetes (nPOD) programme. This evidence concerns the gene TCF7L2 and diabetes mellitus.