CD8A and Behcet disease: CCL4, another possible biomarker (the area under the curve = 0.734~0.823), can detect the BD inflammatory status; higher CCL4 mRNA expression has been observed in patients with BD along with central nervous system involvement and thrombosis, leading to the migration of additional CD8+ T cells, activated mast cells, M1 macrophages and NK cells to the inflammatory sites and aggravating the disease activity (41).