To test the above hypothesis, we measured the protein levels of several pro- (Bax, Bad, Bak, Smac and active caspase-3) and anti-apoptotic factors (Bcl-xL, Bcl-xL/Bak dimer, survivin and Mcl-1), the mRNA and protein expression levels of mitochondrial fission/fusion proteins (Mfn2, Opa1 and Fis1), and the mitochondrial content in peripheral blood mononuclear cells (PBMCs) from BD patients and healthy controls. This evidence concerns the gene FIS1 and Behcet disease.