Although we demonstrated by PCR arrays that several other novel angiogenic genes were significantly altered in RA FLS exposed to hypoxia and the HIF activator DMOG, we focused on the genes EFNA3, leptin, ANGPTL-4 and VEGF as surrogate markers of HIF-induced genes and angiogenesis because they demonstrated consistent and maximal induction on human angiogenesis PCR arrays following hypoxia and DMOG stimulation. This evidence concerns the gene LEP and rheumatoid arthritis.