Anti-NADPH oxidase 5 antibodies are used in the immunodetection of the protein encoded by the NOX5 gene. In humans, the canonical protein has a reported length of 765 amino acid residues and a mass of 86.4 kDa. Its subcellular localization is in the ER and membrane. Alternative splicing is reported to yield 6 different isoforms for this protein. It is reported to be mainly expressed in pachytene spermatocytes of testis and in lymphocyte-rich areas of spleen and lymph nodes. The NADPH oxidase 5 protein is involved with angiogenesis and the apoptotic pathway, among other functions. Other names for this target antigen include NADPH oxidase, EF-hand calcium binding domain 5.