Interestingly, infected bladder-chips immunostained at 2 hr post-introduction of neutrophils (3.5 hr post infection) with antibodies against neutrophil myeloperoxidase (Figure 2H, Figure 2—figure supplement 6A1-A3) and neutrophil elastase (Figure 2I, Figure 2—figure supplement 6B1-B3) showed areas on the epithelial layer which stained positive for each marker (Figure 2H3 and I3). This evidence concerns the gene MPO and infection.