BLZ945 is primarily used in cancer immunotherapy research, specifically as a selective inhibitor of the colony-stimulating factor 1 receptor (CSF-1R). By blocking CSF-1R signaling, it modulates tumor-associated macrophages (TAMs), which often support tumor growth and suppress immune responses. This makes BLZ945 a valuable tool in studies aiming to enhance anti-tumor immunity, especially in combination with other immunotherapies like checkpoint inhibitors. It has shown promise in preclinical models for reducing tumor progression and improving response to treatment in cancers such as glioblastoma and breast cancer. Its application is largely confined to experimental settings to understand macrophage biology and develop novel cancer therapies.