1. Thorsby E: HL-A antigens and genes. I. A study of unrelated Norwegians. Vox Sang 1969, 17:81–92.
2. Khan MA: HLA-B27 and its pathogenic role. J Clin Rheumatol 2008, 14:50–52.
3. Brewerton DA, Hart FD, Nicholls A, et al.: Ankylosing spondylitis and HL-A 27. Lancet 1973, 1:904–907.
4. Schlosstein L, Terasaki PI, Bluestone R, Pearson CM: High association of an HL-A antigen, W27, with ankylosing spondylitis. N Engl J Med 1973, 288:704–706.
5. •• Khan MA: HLA and spondyloarthropathies. In The HLA Complex in Biology and Medicine. Edited by Mehra N. New Delhi, India: Jaypee Brothers Medical Publishers; 2010:422–446. This is a comprehensive review on the association between HLA-B27 and AS, and polymorphism of HLA-B27 in a book just published.