STAT1 and coinfection: Since we previously demonstrated STAT1-mediated IFN signaling as a preferential inducer of Fas/CD95+ at both the protein and transcript level (Farre et al., 2008; Khouri et al., 2018), this study as well as Khouri et al. (submitted) underscore the pivotal role of IFN-driven immune activation in HIV-1 and Leishmania infantum co-infection and its deleterious effect on both AIDS progression and visceral leishmaniasis.