#Acknowledgements
We thank all the groups involved in generating the phosphoproteomics data for their invaluable public resource. We thank Jeff Johnson, Brandon Invergo and Inigo Martincorena for critical reading of the manuscript, Omar Wagih and Francesco Ioirio for their help on implementing some of the methods and Julio Saez-Rodríguez, John Marioni and the rest of the group at the EMBL-EBI for their insightful comments. PB acknowledges support from an HFSP CDA award (CDA00069/2013) and ERC Starting Grant (ERC-2014-STG 638884 – PhosFunc). JV acknowledges support from a Howard Temin Pathway to Independence Award in Cancer Research (NIH K99/R00 CA140789) and an Ellison Medical Foundation New Scholar Award (AG-NS-0953-12).MJ and SDMS are supported by the Medical Research Council (MRC) (MCA652-5PZ600).