SOD2 and Behcet disease: On the other hand, non-HLA regions linked to BD disease have also been identified by genome-wide association studies, along with polymorphisms in certain genes, including those encoding the intercellular adhesion molecule-1, TNF, endothelial nitric oxide synthase, vascular endothelial growth factor, manganese superoxide dismutase (MnSOD), endoplasmic reticulum aminopeptidase 1, cytochrome P450, IL-10, and IL-23 receptor genes (Al-Musawi et al. 2020; Nguyen et al. 2021).