Thus, LamA activity enhances secretion of pro-inflammatory cytokines from hMDMs during infection [Figure 1 (Price et al., 2020)] and impairs L. pneumophila in hMDM through IFN-γ–mediated indolamine-2,3-dioxygenase (IDO) activity (Murray et al., 1989; Price et al., 2020). Here, IDO1 is linked to infection.