Mass spectrometry is a powerful tool for studying proteins in an unbiased and global manner. The current improvements in identification accuracy, sample throughput, and data analysis allow the streamlined application of proteomics in answering diverse biological questions. Our group applies quantitative approaches, which enables us to directly compare thousands of proteins in complex mixtures. These technologies allow us to study changes in protein expression but are also applied in interactomics to identify specific interacting proteins within a vast number of background binders. We combine omics workflows and classical biochemical and molecular biology techniques in several biological areas to advance our knowledge of cellular processes.