The ubiquitin-like protein MNSFβ (Monoclonal Nonspecific Suppressor Factor β), also called FUBI, is encoded by the FAU gene, and is translated as a pro-form consisting of MNSFβ fused to the ribosomal S30 protein. S30 is cleaved in a post-translational reaction, releasing the mature 74 amino acid MNSFβ protein. MNSFβ has a C-terminal gly-gly motif common to many ubiquitin-like proteins. MNSFβ conjugation to Bcl-G has been shown to regulate the ERK1/2-MAPK cascade in macrophage cell lines, and may be implicated in TLR4-mediated signal transduction. Conjugation to endophilin II regulates dectin-1-mediated phagocytosis and inflammatory responses, and may be implicated in TLR2 signaling pathway.