FIS1 and Behcet disease: Supporting these findings, a downregulation of the mitochondrial fusion-related proteins Mfn-2 and Opa-1 and an upregulation of the fission protein Fis-1 were observed in PBMCs from patients with BD [95], suggesting that the imbalance in mitochondrial dynamics might explain the abnormal mitochondrial morphology observed in these patients, which could increase the vulnerability of these individuals to present bioenergetic alterations in acute episodes of the illness.