Anti-Cullin 9 antibodies are used in the immunodetection of the protein encoded by the CUL9 gene. In humans, the canonical protein has a reported length of 2517 amino acid residues and a mass of 281.2 kDa. Its subcellular localization is in the cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. It is widely expressed across many tissue types. A member of the Cullin protein family, it is an important component of a Cul9-RING ubiquitin-protein ligase complex, a complex that mediates ubiquitination and subsequent degradation of BIRC5 and is required to maintain microtubule dynamics and genome integrity. Post-translational modifications have been described, including ubiquitination. Other names for this target antigen include PARC, UbcH7-associated protein 1, p53-associated parkin-like cytoplasmic protein, parkin-like cytoplasmic p53 binding protein, and H7AP1.