Julian obtained his bachelor's degree in natural sciences from Cambridge University and then studied for his PhD in biochemistry in the laboratory of Michael Waterfield at the Imperial Cancer Research Fund in London, where he established in 1984 a link between a retroviral gene (v-erbB) and a cellular growth regulatory protein, the EGF receptor, leading to an ISI 'citation classic' publication.
In 1986, he moved to Robert Weinberg's laboratory at the Whitehead Institute at the Massachusetts Institute of Technology in Cambridge, MA, where he began work on the role of Ras proteins in human cancer.
In 1989 he started his own lab at the Imperial Cancer Research Fund in London, which became Cancer Research UK in 2002 and is now part of the Francis Crick Institute. The lab has provided critical insights into the molecular mechanisms of function and regulation of oncogenic proteins of the Ras family and their importance in human tumours.
Julian has a long held interest in functional genomics, coordinating a number of programmes in this area. He has published over 270 papers in international scientific journals. He was elected to the membership of the European Molecular Biology Organisation in 199, was made a Fellow of the Royal Society in 2005, a Fellow of the Academy of Medical Sciences in 2009, a Fellow of the European Academy of Cancer Sciences in 2010, and an Honorary Fellow of the Royal College of Physicians in 2012. He belongs to the Editorial Boards of the journals Cell, Molecular Cell, Molecular Cancer Research, Cell Cycle, BBA Reviews on Cancer, Cell Research, and PLOS Biology. He is Executive Chairman of the British Association for Cancer.