IFITM3 and influenza: In our previous work, we observed that during HIV-1 and influenza A(H1N1)pdm09 experimental co-infection, HIV-1 particles or HIV-1 surface glycoprotein (gp120), an exogenous CCR5 agonist, reduced influenza replication in an IFITM3-dependent fashion (Mesquita et al., 2014).