FURIN and infection: Figure 8 shows that during the early stages of infection these mutants were also able to maintain their viability growing at the expense of nrdHIEF overexpression, although there were no significant differences in their proliferation indexes and those of the nrdAB mutant. The effect of single nrdR or fur mutants on growth rates and macrophage infection was also evaluated as an additional control (Figures S3 and S4).