In pneumonia, S. aureus α-toxin inhibits the ability of alveolar macrophages (AMs) to clear neutrophils at the site of infection, induces the activation of caspase-3 in lymphocytes and monocytes, mediates cell death, activates caspase-8 and -9, and induces the release of cytochrome C [144,262]. Here, CYCS is linked to pneumonia.