Classically activated (M1) macrophages arise following exposure to interferon-γ (IFNγ) and/or tumor necrosis factor (TNF), express high levels of cytokines IL-1, IL-6, and IL-23, and are adept at producing ROS, all traits as possible which make them highly effective killers during infection or in response to cancer. The gene discussed is IL6; the disease is infection.