Functional genomics has identified numerous genetic drivers of cancer, giving rise to a new generation of targeted therapies. While proteins are the primary functional machinery in cells, the vast majority of modified proteins—including phosphoproteins—lack a known kinase or biological function. We aim to illuminate this “dark phosphoproteome” by finding novel substrates of kinases using phosphoproteomics and validating frequent phosphoproteins in cancer. To this end, we have already discovered new frequently phosphorylated substrates including phosphatases, epigenetic modifiers, and metabolic enzymes, which we will functionally characterize to elucidate novel targetable phosphoprotein drivers of cancer.