Phosphoinositide 3-kinases (PI3Ks) generate lipid second messenger molecules. Class IB PI3K p110gamma (PI3Kgamma) is an attractive drug target for inflammatory disease, for which extensive target validation data from genetically engineered mice are available (1). One of the key issues for PI3Kgamma inhibitors in drug discovery, is their selectivity over other family members of the lipid kinase family (2) and, in fact, protein kinases. We have developed novel and selective inhibitors for PI3Kgamma through the use of a proteomics assay for both screening and selectivity profiling. With this assay, we can monitor quantitatively the interaction of compounds with their kinase targets and off-targets directly from cultured cells or even tissue samples from patients. In a quantitative experiment, the compound is applied over a range of concentrations to cell or tissue lysate, which is subsequently captured on KinobeadsTM, a proprietary affinity matrix which specifically binds hundreds of kinases,not only protein- but also lipid kinases. The unbiased, target profile of the compound is then determined by differential analysis of the captured proteins from treated and untreated samples, by quantitative mass spectrometry using stable isotope labeling. For screening a set of 10 000 compounds against PI3Kgamma, we used as a source for the target the lysate of a PI3Kgamma expressing cell line and quantified the amount of PI3Kgamma captured on the beads by antibody detection. In this way, several hit series were identified and optimized for potency and selectivity. Here we show quantitative proteomic protein and lipid kinase profiles of some of our novel PI3Kgamma inhibitors and how these compare to a range of PI3K inhibitors reported in the literature. We will show an example of potencies of our compound against a set of lipid kinases from primary human leukoctes and how this translates into cellular activity in a neutrophil migration assay.