CXCL8 and infection: Thus, in terms of impairing neutrophil function, the csrS mutant inhibits the migration of neutrophils due to the destruction of IL-8 by the increased expression of scpC (Figure 5) [2]; meanwhile, the rgg mutant does not significantly affect the expression of scpC. On the other hand, since both rgg and csrS genes negatively regulate the expression of slo, infections with these mutants result in damage of neutrophils due to the increased production of SLO in the foci.