Cell-permeable. Acts as an inhibitor of Wnt secretion and processing. It blocks Wnt-dependent signaling (IC₅₀ = 27 nM) by inhibition of the O-acyltransferase Porcn. Porcn is a member of the membrane-bound O-acyltransferase (MBOAT) family, which adds a palmitoyl group to Wnt proteins that is essential to their signaling ability and is required for Wnt secretion.