As gouty arthritis is characterized by extensive macrophage infiltration, we analyzed the presence of macrophages in different phenotypes in the rabbit SM employing RAM11 antibody, that recognizes rabbit macrophages in all different phenotypes; and anti-CD-163, a monocyte and macrophage marker which has been reported to be overexpressed in M2a macrophages (32, 33). The gene discussed is CD163; the disease is gout.