Hedgehog proteins are a group of signaling molecules that play a crucial role in embryonic development and tissue regeneration in many organisms, including humans. They help regulate cell growth, differentiation, and patterning during the formation of various body structures. These proteins are named after the Hedgehog gene, first discovered in fruit flies (Drosophila). When hedgehog proteins bind to their receptors on target cells, they initiate a cascade of cellular responses that influence developmental processes, making them essential for proper organismal development and maintenance.