Specifically, espI (also known as nleA), espS, espO and espM3 were the most abundant NLE transcripts and had distinct expression patterns depending on the conditions (espInleA and espS were induced in DMEM whereas espO and espM3 were induced in LB), but were all significantly upregulated in vivo throughout infection, suggesting an element of co-regulation (Fig. 3b; Supplementary Figure 4b). This evidence concerns the gene TLE4 and infection.