Prof Nick Nicola has made profound and enduring discoveries in the field of the molecular regulation of white blood cells. His early work showed that there were four different hormone-like regulators (colony-stimulating factors, CSFs) of white blood cell production and function, and he led the purification of granulocyte CSF (G-CSF), a protein that is now in routine clinical use to treat more than 20 million cancer patients. His team also cloned three cellular receptors that mediated the actions of the regulators and discovered an important new family of signalling molecules that negatively regulate the actions of CSFs and other regulators.