title: Patients at risk.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Drazen
mesh_terms: D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D061067:Antibodies, Monoclonal, Humanized; D002986:Clinical Trials as Topic; D003424:Crohn Disease / Q000188:drug therapy; D006801:Humans; D007577:JC Virus; D007968:Leukoencephalopathy, Progressive Multifocal / Q000139:chemically induced*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy; D000069442:Natalizumab; D012306:Risk
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000069442:Natalizumab