Serum exosomes from patients with major depressive disorder (MDD) have considerably higher levels of miR-186-5p, miR-3122, and miR-4428, which target serpin family F member 1 (SERPINF1) while having substantially decreased amounts of SERPINF1/pigment epithelium-derived factor, a form of neuronal trophic factor [154]. The gene discussed is SERPINF1; the disease is major depressive disorder.