Comparative quantitative phospho‐proteomic screens have been used successfully as discovery tools to identify important players, cancer drug targets, or signaling branches, e.g. by comparing different types of cancers, wild‐type versus mutant EGFR cells, or stimulation with platelet‐derived growth factor PDGF versus EGF (reviewed in (Kolch & Pitt, 2010)). Here, EGFR is linked to cancer.