The protein known as Saposin B-type (IPR008139) shares similarities with saposin and engages in interactions with lipids. The Saposin-like proteins (SAPLIPs) can do many things, such as being enzymes, cofactors of enzymes involved in lipid metabolism, parts of a pulmonary surfactant that lowers surface tension, part of a complex that controls the phase of Dictyostelium, an antimicrobial effector molecule, or a dendritic growth stimulator.