Anti-assembly factor for spindle microtubules antibodies are used for the immunodetection of the protein encoded by the ASPM gene. In humans, the canonical protein has a reported length of 3477 amino acid residues and a mass of 409.8 kDa. Its subcellular localization is in the nucleus and cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. It is known to be involved in mitotic spindle regulation and coordination of mitotic processes. The gene encoding this protein is implicated in Microcephaly. Other names for this target antigen include abnormal spindle microtubule assembly, asp (abnormal spindle) homolog, microcephaly associated, and abnormal spindle-like microcephaly-associated protein. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.