Anti-PIK3R1 antibodies are used in the immunodetection of the protein phosphoinositide-3-kinase regulatory subunit 1. In humans, the canonical protein has a reported length of 724 amino acid residues and a mass of 83.6 kDa. Up to 5 different isoforms have been reported for this protein. It is notably widely expressed in many tissue types. A member of the PI3K p85 subunit protein family, PIK3R1 is known to bind to activated (phosphorylated) protein-Tyr kinases, through its SH2 domain, and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. Synonyms for this target antigen include GRB1, IMD36, p85, p85-ALPHA, p85alpha, and AGM7. PIK3R1 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Over 3800 citations in the literature describe the use of PIK3R1 antibodies in research. Western Blot is a widely used application for these antibodies. ELISA, Immunofluorescence, and Immunohistochemistry are also common applications.