Formation of complexes between HSPA/HSP70 and the matrix metallopeptidase 9 (MMP-9) was enhanced in murine diabetic retinas and this is of relevance because oxidative stress-induced MMP-9 activation plays a key role in DM-induced mitochondrial abnormalities leading to retinal endothelial cell apoptosis. This evidence concerns the gene MMP9 and diabetes mellitus.