Our research 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. We have also pioneered label-free phosphopeptide quantification in combination with targeted mass spectrometry (SRM) to monitor pathway-specific phosphorylation dynamics. Furthermore, we implement cross-omics approaches to understand system-wide biological responses to perturbations in the light of drug sensitivity and resistance.