GIPC2 and neoplasm: Indeed, in PCa, GIPC1 as a paralogous gene of GIPC2—which is involved in endosomal signaling and tumor cell proliferation, invasion, and metastasis [19, 38]—the PDZ domain of DVL binds the C-terminal region of Fzd receptors and is essential for WNT-signal transduction in PCa tumorigenesis [39].