PRT4165 is primarily used as a potent and selective inhibitor of the RNF43/ZNRF3 ubiquitin ligases, which play key roles in regulating the Wnt signaling pathway. It is widely applied in cancer research, especially in studies involving Wnt-dependent tumors such as colorectal, pancreatic, and liver cancers. By blocking RNF43/ZNRF3, PRT4165 stabilizes Wnt receptors on the cell surface, enhancing Wnt pathway activity in controlled experimental settings. This property makes it a valuable tool for studying Wnt signaling modulation and for evaluating potential therapeutic strategies in regenerative medicine and oncology. It is also used in stem cell research to support the growth and maintenance of epithelial and intestinal organoids, where precise control of Wnt signaling is critical.