OICR-9429 is primarily used in biochemical and pharmacological research as a potent and selective inhibitor of the menin-MLL (mixed lineage leukemia) protein-protein interaction. This interaction plays a critical role in the development of certain types of leukemia, particularly MLL-rearranged (MLL-r) leukemias, which are aggressive forms of acute leukemia affecting both children and adults. By disrupting the menin-MLL binding, OICR-9429 effectively suppresses the expression of key oncogenes such as HOXA9 and MEIS1, which are involved in uncontrolled cell proliferation and leukemogenesis. As a result, it induces cell cycle arrest and apoptosis in leukemia cells, making it a valuable tool compound in the development of targeted cancer therapies. OICR-9429 is widely used in preclinical studies to validate menin inhibition as a therapeutic strategy. It helps researchers understand the downstream effects of blocking the menin-MLL complex and assess antitumor activity in cell lines and animal models. Its selectivity and potency also make it a lead candidate for optimizing drug-like properties in the design of clinical menin inhibitors. In addition to oncology research, OICR-9429 contributes to studies exploring epigenetic regulation and transcriptional control, given the central role of the menin protein in chromatin remodeling and gene expression.