Wnt16 is a member of the Wnt family of secreted glycoproteins, which are crucial for numerous developmental processes, including the regulation of cell growth and differentiation. Notably, Wnt-16 has two mRNA isoforms, Wnt16a and Wnt16b, which exhibit distinct expression patterns; Wnt16a is primarily found in the pancreas, while Wnt16b is abundantly expressed in adult kidney, placenta, brain, heart, and spleen, but not in bone marrow. The differential expression of these isoforms suggests a specialized role for Wnt16b in organ-specific functions and potential implications in developmental biology and disease. Wnt16 is implicated in the pathogenesis of certain leukemias, serving as a downstream target of the E2APbx1 hybrid gene, indicating that Wnt16 mediated autocrine signaling may play a role in the growth of preB acute lymphoblastoid leukemias.