FURIN and infection: levels detected in non-activated J774.2 cells in the presence of wild-type (Fig. 5a i) and fur (Fig. 5a iii) strains were similar, with accumulations of around 3 μM after 21 h of infection whereas levels of  were slightly higher in hmp-infected J774.2 cells (5.5 μM) (Fig. 5a ii).