Other factors are known to regulate ALOX5 activity in vitro but have not been fully integrated into its physiological activation during cell stimulation. ALOX5 binds with the F actin-binding protein, coactin-like protein. Based on in vitro studies, this protein binding serves to stabilize ALOX5 by acting as a Chaperone (protein) or scaffold, thereby averting the enzyme's inactivation to promote its metabolic activity; depending on circumstance such as the presence of phospholipids and levels of ambient Ca2+, this binding also alters the relative levels of hydroperoxy versus epoxide (see arachidonic acid section below) products made by ALOX5. The binding of ALOX5 to membranes as well as its interaction with FLAP likewise cause the enzyme to alter its relative levels of hydroperoxy versus epoxide production, in these cases favoring the production of the epoxide products. The presence of certain diacylglycerols such as 1-oleoyl-2-acetylglycerol, 1-hexadecyl-2-acetyl-"sn"-glycerol, and 1-"O"-hexadecyl-2-acetyl-"sn"-glycerol, and 1,2-dioctanoyl-"sn"-glycerol but not 1-steroyl-2-arachidonyl-"sn"-glyerol increase the catalytic activity of ALOX5 in vitro.