In iNOS-deficient or L-NMMA treated mice, which lack NO, differences in abscess formation were evident only up to three days post-infection (Figure 6C), whereas in mice lacking TNFα, abscess sizes were reduced relative to wild-type mice on Day 5, and mice had largely recovered by seven days post-infection (P<0.05) (Figure 6D). This evidence concerns the gene TNF and abscess.