We previously found that full-body Ptpn2 knockout mice exhibit a significant expansion of a novel mouse AIEC (mAIEC).25 The aim of this study was to identify whether loss of PTPN2 activity compromises macrophage-mediated host defences against AIEC and to assess the mechanisms by which loss of PTPN2, or the presence of SNP rs1893217 SNP, compromises the ability of macrophages to clear AIEC infections. The gene discussed is PTPN2; the disease is infection.