GSK1059615 is primarily utilized in biochemical research as a potent and selective inhibitor of PI3K (phosphoinositide 3-kinase), particularly targeting the p110 delta isoform. This makes it a valuable tool for studying the PI3K signaling pathway, which plays a critical role in cell growth, survival, and metabolism. Researchers use it to investigate the role of PI3K in various diseases, including cancer, immune disorders, and inflammatory conditions. Its selectivity allows for precise exploration of the p110 delta isoform's function in B-cell malignancies and immune cell regulation. Additionally, GSK1059615 is employed in drug discovery and development to evaluate the therapeutic potential of PI3K inhibitors in preclinical studies.