An orally available inhibitor of porcupine (PORCN), with potential antineoplastic activity. Upon oral administration, WNT974 binds to and inhibits PORCN in the endoplasmic reticulum (ER), which blocks post-translational acylation of Wnt ligands and inhibits their secretion. This prevents the activation of Wnt ligands, interferes with Wnt-mediated signaling, and inhibits cell growth in Wnt-driven tumors. Porcupine, a membrane-bound O-acyltransferase (MBOAT), is required for the palmitoylation of Wnt ligands, and plays a key role in Wnt ligand secretion and activity. Wnt signaling is dysregulated in a variety of cancers.