We approached our hypothesis by interrogating the association of DOC2B with EVs derived from human plasma, EVs released by human islets (sourced from individuals with no diabetes (ND), cultured ex vivo) and EVs from clonal cultured β-cells relative to other cells that regulate glucose homeostasis and that also functionally require DOC2B for intracellular vesicle trafficking mechanisms (e.g., neuronal-like SH-SY5Y cells, and skeletal muscle L6-GLUT4myc myotube cells). This evidence concerns the gene DOC2B and diabetes mellitus.