Signaling pathways play critical roles in executing and controlling important biological processes within cells. The dysregulation of signaling pathways modulates chromatin modifications to regulate the epigenome, thereby contributing to tumorigenesis and metastasis Despite their cancer-related importance, current studies are limited to the investigation of the signaling cascade and how to shut this down in a cancer context. Yet the ultimate effect of PI3K/AKT/mTOR activation cascades on chromatin composition have not been previously investigated. To unravel DBP function upon different pathway inhibitors, in this study, we 1) optimized the iPOC strategy, 2) assessed both the specificity and sensitivity of the approach, and 3) performed comprehensive quantitative chromatin proteomic analysis to identify the dynamics of DNA-bound proteome upon treatment with PI3K, AKT or mTOR inhibitors.