B and T cell-promoting effects of both cytokines IL-6 and IL-1β, may furthermore play a role during inflammatory responses in CRMO, since neutrophils and monocytes (which produce IL-6 and IL-1β) are the predominant cells in the acute phase of bone inflammation, while later stages are characterized by lymphocyte and plasma cell infiltration (2). The gene discussed is IL1B; the disease is chronic recurrent multifocal osteomyelitis.