Our group is interested in molecular mechanism that regulate signaling molecules and in the exploration of such mechanism for the rational design of inhibitors. We particularly focus on protein kinases, epigenetic reader domains of the bromodomain family, phosphatases and complexes of these targets with regulatory proteins. Protein kinases have attracted a lot of attention as targets of therapeutic intervention in particular for the treatment of cancer and inflammation. This family also constitutes one of the largest protein families currently targeted by pharmaceutical industry. Due to the largely conserved active site and the large number of protein kinases in the human genome, development of specific inhibitors is a challenging task. However, structures of kinase inhibitor complexes have identified a number of strategies (such as inhibitor binding to inactive conformations and allosteric sites) that can be explored for the design of selective inhibitors. To facilitate drug development we have screened all kinases we have worked on against a library of commercially available ATP mimetic inhibitors. The large amount of accumulated screening data provides insight about the drugability of a certain target, initial hits for further development of inhibitors and cross-reactivity of commercially available inhibitors that are often used as tools in cell biology.