In first stage study, the frequency of the CIITA//rs12932187 C allele (Pc = 1.668 × 10−2, OR = 0.713, 95% CI = 0.591–0.861) and NOD1//rs2075818 G allele (Pc = 4.694E-02, OR = 0.698, 95% CI = 0.562–0.868) were decreased in BD patients compared to controls (Table 2). The gene discussed is NOD1; the disease is Behcet disease.