John received his PhD in 1998 from the University of Melbourne. He undertook his postdoctoral training at Montefiore Medical Center/Albert Einstein College of Medicine in the Bronx, New York. In 2001 he established his independent laboratory at Albert Einstein as Assistant Professor of Medicine, and in 2008 was appointed Associate Professor of Medicine. In 2008 he joined the Ludwig Institute in Melbourne as Head of the Oncogenic Transcription Laboratory.
John is currently Professor at the School of Cancer Medicine at La Trobe University and Head of the Oncogenic Transcription Laboratory at the Olivia Newton-John Cancer Research Institute. He is a National Health and Medical Research Council Senior Research Fellow.