Interferon-induced transmembrane proteins in cancer and virus biology: a membrane perspective

The interferon-induced transmembrane proteins (IFITMs) are a family of potent broad-spectrum antiviral factors that restrict enveloped viruses primarily by altering the biophysical properties of membranes, thereby preventing viral-cellular fusion. While their antiviral mechanisms are well established, increasing evidence suggests that IFITMs can also play important roles in cancer biology by remodeling of the cancer cell surface proteome and by modulating signaling pathways involved in proliferation, cell survival, and metastasis. In this review, we summarize the diverse biological functions attributed to IFITMs over the years; we highlight the salient aspects of their biology; and we propose a unifying conceptual framework in which seemingly diverse functions of IFITMs in virology and cancer biology can be understood through their capacity to regulate the behavior of membranes.