Involved in negative regulation of viral entry into host cell and response to virus. Acts upstream of or within defense response to other organism; negative regulation of cell population proliferation; and receptor-mediated endocytosis. Located in several cellular components, including apical part of cell; cell surface; and endoplasmic reticulum. Is expressed in several structures, including alimentary system; egg cylinder; embryo ectoderm; genitourinary system; and mesenchyme derived from lateral plate. Human ortholog(s) of this gene implicated in COVID-19; adenosquamous gallbladder carcinoma; and gallbladder adenocarcinoma. Orthologous to several human genes including IFITM3 (interferon induced transmembrane protein 3). [provided by Alliance of Genome Resources, Apr 2022]