John Marioni, Senior Group Leader at the University of Cambridge, is a world-leader in the field of computational biology, making seminal contributions especially in the area of single cell genomics. He has developed innovative and widely used methods for normalisation, integration of datasets and downstream analyses and has applied these to understand how cells commit to different fates in the context of early development and in cancer. The computational tools developed by Marioni are amongst the most widely-used in biology. He is also Head of Research at EMBL-EBI, where he oversees groups working across diverse areas of computational biology.