酸素分子O2を１電子還元してO2-を生成する酵素である。

膜貫通部の３番目と５番目にヒスチジンがありここにヘム鉄が配位する

NOXのC末端で細胞質に存在するところにFAD結合部位とNADPH結合部位がある

NADPH oxidase 1 is an enzyme that in humans is encoded by the NOX1 gene.

NOX1 is a homolog of the catalytic subunit of the superoxide-generating NADPH oxidase of phagocytes, gp91phox. Two transcript variants encoding different isoforms have been found for this gene.

NADPH oxidase 2 (Nox2), also known as cytochrome b(558) subunit beta or Cytochrome b-245 heavy chain, is a protein that in humans is encoded by the NOX2 gene (also called CYBB gene). The protein is a superoxide generating enzyme which forms reactive oxygen species (ROS).

NADPH oxidase 3 is an enzyme that in humans is encoded by the NOX3 gene.

NADPH oxidases, such as NOX3, are plasma membrane-associated enzymes found in many cell types. They catalyze the production of superoxide by a 1-electron reduction of oxygen, using NADPH as the electron donor.[supplied by OMIM]

NADPH oxidase 4 is an enzyme that in humans is encoded by the NOX4 gene, and is a member of the NOX family of NADPH oxidases.

Oxygen sensing is essential for homeostasis in all aerobic organisms. A phagocyte-type oxidase, similar to that responsible for the production of large amounts of reactive oxygen species (ROS) in neutrophil granulocytes, with resultant antimicrobial activity, has been postulated to function in the kidney as an oxygen sensor that regulates the synthesis of erythropoietin in the renal cortex. Nox4 protects the vasculature against inflammatory stress. Nox-dependent reactive oxygen species modulation by amino endoperoxides can induce apoptosis in high Nox4-expressing cancer cells.  A study found that NOX4 facilitates certain beneficial adaptive responses to exercise mediated by ROS. Moreover, reductions in skeletal muscle NOX4 in aging and obesity was shown to contribute to the development of insulin resistance and may promote oxidative stress.

NADPH oxidase, EF-hand calcium binding domain 5, also known as NOX5, is a protein which in humans is encoded by the NOX5 gene.

NOX5 is a novel NADPH oxidase that generates superoxide. Nox5 interacts with c-abl, superoxide production leads to phosphorylation of c-abl, while inhibition of c-abl kinase activity inhibits Nox5 superoxide production.

Dual oxidase 1, also known as DUOX1 or ThOX1 (for thyroid oxidase), is an enzyme which in humans is encoded by the DUOX1 gene.  DUOX1 was first identified in the mammalian thyroid gland.  In humans, two isoforms are found; hDUOX1 and hDUOX2. Human DUOX protein localization is not exclusive to thyroid tissue; hDUOX1 is prominent in airway epithelial cells and hDUOX2 in the salivary glands and gastrointestinal tract.

Dual oxidase 2, also known as DUOX2 or ThOX2 (for thyroid oxidase), is an enzyme that in humans is encoded by the DUOX2 gene.  Dual oxidase is an enzyme that was first identified in the mammalian thyroid gland. In humans, two isoforms are found; hDUOX1 and hDUOX2 (this enzyme). The protein location is not exclusive to thyroid tissue; hDUOX1 is prominent in airway epithelial cells and hDUOX2 in the salivary glands and gastrointestinal tract