The Wnt signaling pathway, an evolutionarily conserved signal transduction pathway, is widely present in invertebrates and vertebrates. The Wnt signaling pathway plays a crucial role in early embryonic development, organogenesis, tissue repair, and many other physiological processes. The mutation of key proteins involved in this pathway can lead to abnormal activation of signals, and potentially induces the occurrence of cancer. In 1982, R. Nusse and H.E. Varmus identified the first Wnt gene from a mouse mammary tumor and named it Int1 (integration 1). Continued research found that the mouse Int and Drosophila Wingless (Wg) genes are homeotic, and thus combined their names to Wnt. H.E. Varmus himself also won the 1989 Nobel Prize in Physiology or Medicine for his great contribution in oncology.