Maarten Altelaar is a Professor at the Department of Pharmaceutical Sciences of the Utrecht University. The research in his group focuses on the development and implementation of innovative mass spectrometric methods for the efficient and detailed characterization of proteins, protein complexes and their post-translational modifications (PTMs) in relation to their biological function in health and disease. Main emphasis is on the improvement of sensitivity, specificity and throughput of proteomics technology for the investigation of cellular signaling networks. His lab has pioneered label-free phosphopeptide quantification in combination with targeted mass spectrometry (SRM) to monitor pathway-specific phosphorylation dynamics. Furthermore, his group implements cross-omics approaches to understand system-wide biological responses to perturbations in the light of drug sensitivity and resistance. In 2013 he received a VIDI grant to work on proteome-wide crosstalk mechanisms in cancer signaling and drug resistance. He is involved in large consortia such as the Netherlands Proteomics Centre, X-Omics and PrimeXS and is currently the treasurer of the International Mass Spectrometry Foundation.