Finally, upon infection of D. discoideum producing 2×PHFAPP-mCherry and Arf1-GFP with L. pneumophila ΔralF, the PtdIns(4)P probe labeled LCVs harboring the mutant strain to the same extent as LCVs harboring the parental strain, while Arf1-GFP was not observable on pathogen vacuoles (Fig. 5C). Here, ARF1 is linked to infection.