We are interested in the signaling mechanisms by the Wnt family of secreted molecules. It has become clear that Wnt proteins are one of about half a dozen major families of conserved signaling proteins that guide embryonic development and adult homeostasis. We primarily focus on Wnt signaling in early vertebrate embryonic patterning, in cell polarity regulation (planar cell polarity and neuronal polarity), and in stem cell and cancer biology. We employ molecular, biochemical, embryological and genetic approaches in several experimental systems, including Xenopus embryos, mammalian and Drosophila cell cultures, and knockout mice. Our main projects are focused on: 1) Wnt/beta-catenin signaling 2) Wnt signaling in cell polarity 3) Wnt signaling in stem cell biology, cancer and diseases.