Table 1.

Localization, function and activation of NADPH oxidase (Nox) isoforms.

Isoforms	Tissue expression	Subunits	Activation	Functions	Refs
Nox1	colon epithelium, vascular smooth muscle, endothelial cells, kidney	NoxO1 NoxA1 p22phox Rac	PKC, PLD, growth factors	proliferation, migration, apoptosis	(Clempus and Griendling, 2006; Hoidal et al., 2003; Mittal et al., 2007)
Nox2	phagocytes, endothelial cells, pulmonary arteries, heart	p47phox p67phox p22phox Rac	PKC	immunity, HPV	(Clempus and Griendling, 2006; Lassegue and Griendling, 2010; Liu et al., 2006; Mittal et al., 2007)
Nox3	inner ear non vascular	p22phox NoxO1	constitutive		(Hoidal et al., 2003; Lassegue and Griendling, 2010)
Nox4	vascular and airway smooth muscle, kidney	p22phox	constitutive, Ang II, TGFβ, hypoxia,	proliferation, migration	(Clempus and Griendling, 2006; Liu et al., 2006; Mittal et al., 2007)
Nox5	spleen, kidney, testes, lung, cancers not found in rodents	p22phox	Ca2+	contraction, cell growth	(Fulton, 2009)