MPO and neoplasm: This stands in contrast to a “transformed” lesion (black arrow) of a HU-pretreated rabbit sacrificed in healthy condition 8 days after spore injection (Figure 6C), which upon closer examination was free of tumor and germinating bacteria but predominantly filled with neutrophils as demonstrated by antimyeloperoxidase (MPO) IHC (brown) (Figure 6D, Supplementary Figure 5A&B).