Anti-SMAP4 antibodies enable researchers to detect and measure the SMAP4 antigen in biological samples. This target is a reported synonym of the MFSD1 gene, which encodes major facilitator superfamily domain containing 1. This protein is known to function in protein stabilization, among other biological roles. The human version of SMAP4 has a canonical amino acid length of 465 residues and a protein mass of 51.2 kilodaltons, although 6 isoforms have been identified. It is reported to be localized in the lysosomes of cells and notably expressed in many tissues, such as the appendix and bronchus. SMAP4 is a member of the Major facilitator protein superfamily.