Interferon-induced transmembrane protein 1 (CD225) is an IFN-induced antiviral protein that mediates cellular innate immunity to major human pathogens, namely influenza A H1N1 virus, SARS-CoV, West Nile virus, Ebola virus and dengue virus by inhibiting the early step(s) of replication. CD225 plays a key role in the antiproliferative action of IFN-gamma either by inhibiting the ERK activation or by arresting cell growth in G1 phase in a p53-dependent manner. CD225 is implicated in the control of cell growth. CD225 is a component of a multimeric complex involved in the transduction of antiproliferative and homotypic adhesion signals.