An interesting finding was seen in both datasets: the expression of the insulin gene in β-cells of T2D patients positively correlated with the expression of CALR, a calcium-binding chaperone that promotes folding, oligomeric assembly, and quality control in the ER (https://www.uniprot.org/, accession number P27797, accessed on 7 December 2023), and this cor-relation was not observed in non-diabetic samples. This evidence concerns the gene CALR and type 2 diabetes mellitus.