IAPP and type 1 diabetes mellitus: While UMAP analyses, by design, foreground discriminating cluster features, a comparison of islet properties within individual clusters across T1D stages also discloses some revealing differences: first, in transition from Ctrl to T1DS stage, ProINS and IAPP but less so INS content is progressively reduced in cluster I, II and III ICIs suggesting that modulation of ProINS and IAPP expression reports T1D pathogenetic processes with particular sensitivity (Figs.S5F/H).