FURIN and infection: Fur derepresses the expression of multiple iron acquisition systems as soon as it senses that iron is depleted, and the pathogenic bacteria counterattack through robbing host iron sources via producing siderophores, such as pyoverdine, salmochelin, and staphyloferrin, which further result in virulence increase during infection by enhancing its proliferation (Saha et al., 2013), regulating the production of virulence factors (Llamas et al., 2014), and evading host innate immune response (Palmer and Skaar, 2016).