In this article, the author discusses various aspects of cell signalling gene Wnt/ Wingless in the animal kingdom concerning its role in the fruit-fly Drosophila population, Drosophila's body segmentation and segment polarity, and human diseases and cancer. It mentions that a family of seven wingless genes has been found in Drosophila. It informs that Wnt signalling is associated with a number of human diseases including cancer.