Normal cells use the enzymes mainly to catalyze the oxidation of harmful aldehydes from various precursors to carboxyl acids. Cancer cells may require ALDH activity for metabolism of therapeutic drugs and development of drug resistance.
Eðlilegar frumur nýta sér ALDH virknina til verndar gegn skaðlegum áhrifum aldehýða en krabbameinsfrumurnar mögulega til niðurbrots á krabbameinslyfjum og þróun á lyfjaónæmi.