Anti-squalene epoxidase antibodies are used in the immunodetection of the protein encoded by the SQLE gene. In humans, the canonical protein has a reported length of 574 amino acid residues and a mass of 63.9 kDa. Its subcellular localization is in the ER and membrane. It is notably expressed in liver. A member of the Squalene monooxygenase protein family, it is known to catalyze the stereospecific oxidation of squalene to (S)-2,3-epoxysqualene, and is considered to be a rate-limiting enzyme in steroid biosynthesis. Post-translational modifications have been described, including ubiquitination. Other names for this target antigen include squalene monooxygenase and SE.