The G-1 column, which is filled with cellulose acetate spherical beads of 2 mm diameter, is a new type of extracorporeal perfusion device originally designed to remove granulocytes from the venous circulation of patients with rheumatoid arthritis. A dramatic improvement in clinical symptoms was seen after treatment with the G-1 column in two successive clinical trials. Early effects include pain relief, reduction in the swollen joints, and a continued decrease in inflammation as a late effect. The results were further confirmed in the adjuvant arthritic rat model. G-1 beads adsorb some amounts of platelets at the beginning and then about a quarter of circulating neutrophils, monocytes, natural killer cells, and B cells, but not T cells. Various factors released from blood cells during transit through the column must have influenced the cells including lymphocytes which passed through the column. G-column actually eliminates some parts of aggressive leukocytes, but a more interesting story is the modification of blood components, which occurred in the G-1 column, and when returned to the patients, may have ameliorated the unbalanced homeostatic network and induced acceleration of healing.