The UFC1 gene encodes Ubiquitin-Fold Modifier-Conjugating Enzyme 1, a protein that acts as an E2-like enzyme that conjugates with UFM1 to form an intermediate. This conjugation with UFM1 takes place via a thioester linkage at the UFC1 protein’s active site cysteine residue. UFC1 is thus involved in the processes of protein ufmylation (the covalent attachment of the ubiquitin-like UFM1 to another protein) and protein K69-linked ufmylation (the attachment of a UFM1 polymer to a protein). UFC1 is a component of the extracellular exosome and due to its molecular function, it is believed to be involved in the response to endoplasmic reticulum stress.