Rodbell and Gilman found that a transducer, the G protein, provided the link between the hormone receptor and the amplifier of the signal. They used genetic and biochemical techniques to identify the G-protein. They observed a mutated lymphoma (defective) cell that had normal receptor and amplifier but lacked a transducer (G-protein). Discovery of G-proteins allows for proper medical diagnosis by filling in the gap. They were awarded Nobel Prize (medicine) in 1994 for the discovery.