We, therefore, fine-mapped the UBAC2 using 25 SNPs and found that 6 SNPs, that is, rs3825427, rs1927726, rs9517668, rs9554581, rs9517701 and rs9517699, were associated with BD (P ≤0.05/25 = 0.002) (Table 4, Figure 1 and Additional file 1). This evidence concerns the gene UBAC2 and Behcet disease.