ZMPSTE24 and infection: Dorf’s group showed that, like the IFITMs with which it interacts, overexpression of ZMPSTE24 robustly protects cells from infection by many pathogenic enveloped viruses, but not all (e.g., murine leukemia virus [MLV] is an exception), and that its proteolytic activity is not needed in this role (29, 30).