The ex vivo invasion of FLS is directly correlated with disease severity in patients with RA [37, 69, 70], and we found that FLS isolated from rats with PIA or CIA that were treated with Kv1.3 or KCa1.1 blockers, alone or in combination, exhibited reduced ex vivo invasion compared with vehicle-treated rats. This evidence concerns the gene KCNMA1 and rheumatoid arthritis.