Function: A2ML1 is a new member of the alpha 2-macroglobulin protease inhibitor family, and shares most the characteristics of this family. It is the first family member detected in the epidermis and may play an important role during desquamation by inhibiting extracellular proteases. The alpha-macroglobulin (AM) superfamily of proteins contains both complement components and protease inhibitors, including A2M and A2ML1. AM proteins display a unique trap mechanism of inhibition, by which the AM inhibitor undergoes a major conformational change upon its cleavage by a protease, thus trapping the protease and blocking it from subsequent substrate binding.