ARCN1 and susceptibility to pneumonia measurement: To this end, we selected two of the mutant strains and their complemented derivatives to test in a murine pneumonia model; the cusR and copD mutant strains were selected due to their high level of copper sensitivity and successful in vitro complementation (Figure 2), as well as their phenotypic differences from the wild-type strain in all other assays, including virulence in G. mellonella (Figures 5–7).