Professor Michael Waters is an outstanding Australian scientist with an international reputation in growth hormone action. He was the first to purify and characterise the growth hormone receptor, and, with partners, to clone it. He mapped its tissue distribution, and from that developed new physiologies of growth hormone action, including its role in activating neural stem cells in response to exercise. Michael has elucidated the signals required for key growth hormone actions, and uncovered the molecular basis for receptor activation of its kinase, which has been described as a new paradigm in cytokine receptor signalling.