Angel Lopez is an outstanding Australian scientist with an international reputation in human cytokines or growth factors, particularly on studies of cytokine families with a shared receptor subunit. Using as a prototype the haemopoietic ßc family of cytokines that comprises GM-CSF, IL-3 and IL-5, he has made several breakthroughs that have illuminated how these cytokines exert their biological activities and revealed new paradigms that apply to the cytokine superfamily at large. His unique insights into cytokine function, receptor recognition and signalling have paved the way for the development of novel drugs for the treatment of usually fatal myeloid leukaemia’s and debilitating chronic inflammatory diseases.