Serpin F1, also known as PEDF, is a secreted glycoprotein that belongs to the clade F subfamily of the serpin family of proteinase inhibitors. Because it does not display any serine protease inhibitory activity it belongs to a second group, separate from other serpin family members that do possess typical protease inhibitor function. Serpin F1 is expressed in many tissues including lung, liver, skin, heart and ovary, and it has diverse functions. These include anti-angiogenic, neuroprotective, and anti-carcinogenic activities. The protein has been mapped and different regions have been associated with its differing roles. It binds to the PEDF receptor, and may have other receptor targets.