Ubiquitin-fold Modifier 1 (UFM1), also known as BM-002, is an 85 amino acid (aa) member of the ubiquitin-like protein family that has a predicted molecular weight of 9.1 kDa. Human and mouse UFM1 share 100% aa sequence identity and are primarily localized in the nucleus, but can also be detected in the cytoplasm and the endoplasmic reticulum (ER). ER localization of UFM1 appears to be dependent on the co-expression of UFBP1. Initially expressed as an inactive precursor, UFM1 undergoes proteolytic cleavage at the C-terminus to expose a conserved glycine residue that is necessary for UFM1 conjugation to target proteins. Conjugation of UFM1 to target proteins requires a UFM1-activating (E1) enzyme, a UFM1-conjugating (E2) enzyme and a UFM1 ligase (E3). UFM1 has been shown to be a mediator of ER stress-induced cancer and to promote the pathogenesis of Leishmania.