Wnt signaling is a critical pathway in animal development, with mutations in Wnt genes leading to diverse phenotypes in mice, C. elegans, and Drosophila. Wnt proteins regulate processes such as embryonic induction, cell polarity, and cell fate specification. Recent advances have clarified the molecular mechanisms of Wnt signaling, including the identification of cell-surface receptors and the pathway by which signals are relayed to the nucleus. These insights have revealed that Wnt signaling is conserved across species, with components involved in human cancer. The review summarizes current understanding of Wnt function and signaling mechanisms, emphasizing recent findings and remaining questions. Wnt genes are conserved across species, with homologous genes in various organisms. The Drosophila Wg protein is a well-studied member of the Wnt family, and its signaling pathway has been elucidated. Mutations in Wg and other Wnt genes lead to segment polarity defects, and recent studies have focused on understanding the biochemical relationships between these proteins. The Wnt signaling pathway is also involved in cancer, with mutations in genes such as APC and β-catenin contributing to tumorigenesis. The review highlights the role of Wnt proteins in development and disease, as well as the importance of receptors such as Fz proteins in Wnt signaling. The mechanism of Wnt signaling involves the interaction of Wnt proteins with cell-surface receptors, leading to the activation of downstream signaling components such as Dsh and Arm/β-catenin. The role of proteoglycans in Wnt signaling is also discussed, as well as the involvement of other proteins such as Axin and GSK-3. The review provides a comprehensive overview of Wnt signaling, emphasizing its importance in development and disease.Wnt signaling is a critical pathway in animal development, with mutations in Wnt genes leading to diverse phenotypes in mice, C. elegans, and Drosophila. Wnt proteins regulate processes such as embryonic induction, cell polarity, and cell fate specification. Recent advances have clarified the molecular mechanisms of Wnt signaling, including the identification of cell-surface receptors and the pathway by which signals are relayed to the nucleus. These insights have revealed that Wnt signaling is conserved across species, with components involved in human cancer. The review summarizes current understanding of Wnt function and signaling mechanisms, emphasizing recent findings and remaining questions. Wnt genes are conserved across species, with homologous genes in various organisms. The Drosophila Wg protein is a well-studied member of the Wnt family, and its signaling pathway has been elucidated. Mutations in Wg and other Wnt genes lead to segment polarity defects, and recent studies have focused on understanding the biochemical relationships between these proteins. The Wnt signaling pathway is also involved in cancer, with mutations in genes such as APC and β-catenin contributing to tumorigenesis. The review highlights the role of Wnt proteins in development and disease, as well as the importance of receptors such as Fz proteins in Wnt signaling. The mechanism of Wnt signaling involves the interaction of Wnt proteins with cell-surface receptors, leading to the activation of downstream signaling components such as Dsh and Arm/β-catenin. The role of proteoglycans in Wnt signaling is also discussed, as well as the involvement of other proteins such as Axin and GSK-3. The review provides a comprehensive overview of Wnt signaling, emphasizing its importance in development and disease.