To determine whether cilostazol suppresses HMGB1-induced upregulations of HIF-1α mRNA and protein, we pretreated RA SFs with cilostazol (1, 10 and 30 μM) for 4 hr prior to culturing them with 100 ng/ml HMGB1 for 12 hr. The gene discussed is HMGB1; the disease is rheumatoid arthritis.