IL1B and Salmonella Infections: At 3 hpi, infected larvae showed elevated levels of expression of pro-inflammatory cytokines: interleukin-1 beta (il-1b), tumor necrosis factor a and b (tnfa and tnfb, two orthologs of mammalian TNF), interleukin-8 (il-8), and of the inflammation marker matrix metalloproteinase 9 (mmp9) (Figure 2A), consistent with previous findings in zebrafish models of systemic Salmonella infection (Stockhammer et al., 2009).