Abstract: Cell signaling is one of the most fundamental processes that controls human health, and yet the mechanics of this intricate system is largely unappreciated. This is stunning because the primary agents for this system, membrane receptors, are known to account for approximately 1/3 of all approved human drugs. Often, the receptors themselves are known before the discovery of their endogenous ligands. In this proposal, we detail a systematic method for the identification of the targets of fatty acid amides, a highly regulated class of molecules known to engage in at least two signaling processes. The bulk of the other members of this class of compounds have never been paired with their receptors, and uncovering this information has tremendous potential for identifying new therapeutic targets and improving drug discovery efforts by revealing potentially undesirable off-target candidates.