Furthermore, in patients with Crohn's disease HBO2 treatment has shown to modulate the proinflammatory response by an initial elevation of IL‐1 but during courses of HBO2 decreasing IL‐1; indicating that prolonged HBO2 treatment may initially exhaust monocytes of stored IL‐1 subsequently leading to an inhibition of cytokine production and/or secretion (Weisz et al., 1997). The gene discussed is IL1B; the disease is Crohn disease.