HIF1A and rheumatoid arthritis: Following the staining procedure described by Zhong and Semenza [21] and using monoclonal antibody HIF-1alpha67sup we detected a nuclear staining of HIF-1α in synovial tissues from all RA patients, which was not restricted to the lining layer but had a diffuse pattern throughout the tissue (figure 1A and 1D, see arrows) [22].