1 and the experiments were quickly repeated by many people in the field, either out of a sense of disbelief or just because they were so easy and exciting to do.
Today INT-1 is called WNT-1. Researchers realized that INT-1 and the Wingless gene in fruit flies were the same, so they combined the names to WNT. In fact, an entire family of 19 Wnt glycoproteins has now been identified in mammals alone. Each of these glycoproteins is expressed in spatially and temporally restricted patterns in embryos and adults. We now know that the Wnts are secreted factors that activate multiple signaling pathways in cells by binding to receptors known as the Frizzled receptors, as well as to other transmembrane proteins.
In the 20 years that followed that first experiment, others and I have tried to understand how Wnt operates. We have learned that the normal roles ...
