Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram negative, motile bacterium capable of infecting human, animal or bird hosts. S. Typhimurium infects epithelial cells and macrophages intracellularly, enabled by use of Type III Secretion Systems (T3SSs) to translocate effector proteins directly into the host cell cytosol. These effector proteins are used to exert a range of pathogenic activities, including mediating changes to innate immune pathways, inhibiting programmed cell death responses and promoting host cell survival1. Research from the Pearson Group (unpublished) has indicated that infection of immortalised mouse macrophages (RAW264.7 cells) with wild type S. Typhimurium SL1344 induces the degradation of cellular inhibitor of apoptosis protein 1 (cIAP1), an important host cell adaptor of tumour necrosis factor receptor 1 (TNFR1) signalling and an inhibitor of apoptotic cell death. This cIAP1 degradation was associated with functional Salmonella Pathogenicity Island 1 (SPI-1) effector translocation after 10 hours of infection, and was not prevented by pan‑caspase, proteasomal or lysosomal inhibitors. Consistent with our understanding of cIAP1 mediated inhibition of apoptosis, LDH assay indicated a strong association between loss of cIAP1 and increased cytotoxicity at 19 hours post infection. Later experiments detected a low molecular weight peptide specific for our cIAP1 antibody, possibly indicating that a SPI-1 effector directly cleaved cIAP1 to produce this cleavage product. Together, these data provide early support for our hypothesis that cIAP1 depletion was induced by a SPI-1 effector following infection with S. Typhimurium in order to promote host cell death, and potentially dissemination of the bacterium.