BDNF and Behcet disease: Evidence suggests that BD involves alterations in numerous biological systems, including disrupted structural and functional brain connectivity (49–51), oxidative stress (52), mitochondrial dysfunction (53), inflammation (54), circadian rhythm disturbances (55), dopamine dysregulation (56), neurotrophic system abnormalities (e.g., elevated brain-derived neurotrophic factor levels), and calcium signaling disruptions (57–59).