\section{Acknowledgements}\label{acknowledgements}

We thank Jeff Johnson, Brandon Invergo and Inigo Martincorena for
critical reading of the manuscript. We would also like to thank 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 an 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).
