MPP-9 activation in the retina is considered one of the key events that damage mitochondrial function and activate the apoptotic machinery [81,82]; according to mechanistic interpretation, diabetes causes epigenetic changes on MPP-9 secondary to H3K9 hypomethylation and increased acetylation on lysine (K9) at the MPP-9 promoter. Here, MPHOSPH9 is linked to diabetes mellitus.