Sazonovs et al. [136] found that the presence of one or two copies of the HLA-DQA1*05 alleles conferred a 2-fold increased risk of developing immunogenicity to anti-TNFα therapy in patients with IBD, regardless of the type of anti-TNFα (ADA or IFX) or concomitant treatment with immunomodulators. The gene discussed is ADA; the disease is inflammatory bowel disease.