ENPP2 and pulmonary fibrosis: However, larger randomized clinical trials are needed to determine its efficacy. Autotaxin is an enzyme responsible for the conversion of lysophospholipids (lysophosphatidic acid [LPA] from the hydrolysis of lysophosphatidic choline [LPC], the latter of which is produced in the liver). LPA is believed to stimulate dendritic cell differentiation and smooth muscle contraction and prevents apoptosis. Autotaxin may in part be responsible for the “chronic wound response." Little is known about the expression and function of autotaxin, LPA, and LPC in human diseases such as pulmonary fibrosis [66].