MCL1 and infection: C. pneumoniae relies on the activation of the IL-8-mediated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway to stabilize myeloid cell leukemia-1 (MCL-1) and inhibit the spontaneous apoptosis of neutrophils, which act as a transport vehicle and are beneficial for C. pneumoniae to establish a productive infection during the initial phase of infection (118).