Of particular interest was the prostaglandin H2 D-isomerase coding PTGDS gene the expression of which was up-regulated in islets from T2D donors; it significantly correlated with INS, GCG and IAPP expression and associated with HbA1c levels (Figs 2, 4, 5, 6, and S9). This evidence concerns the gene IAPP and type 2 diabetes mellitus.