Oxidizes medium and long chain aldehydes into non-toxic fatty acids. an aldehyde + H2O + NAD(+) = a carboxylate + 2 H(+) + NADH 2 H(+) + hexadecanoate + NADH = H2O + hexadecanal + NAD(+) H2O + NAD(+) + octanal = 2 H(+) + NADH + octanoate Expressed in testis, kidney, small intestine, spleen, white adipose tissue, liver and lung. Geranylgeranylation is important for membrane localization and enzyme activity. Belongs to the aldehyde dehydrogenase family. Probable cloning artifact.