CFI-400945 is a potent and selective inhibitor of the polo-like kinase 4 (PLK4), a key regulator of centriole duplication in cells. Its primary application lies in cancer research, particularly as a targeted therapeutic agent in oncology. By inhibiting PLK4, CFI-400945 disrupts centrosome amplification, leading to mitotic defects and cell death in tumor cells that rely on abnormal centrosome numbers for survival. It has shown promising antiproliferative activity in preclinical models of solid tumors, including breast, ovarian, and lung cancers, especially in tumors with genetic instability or p53 mutations. Due to its mechanism, CFI-400945 is being investigated for use in cancers resistant to conventional chemotherapies. It is also used as a research tool to study centrosome biology, mitotic regulation, and mechanisms of tumor cell proliferation. Ongoing studies focus on optimizing its delivery and evaluating its efficacy in combination with other anticancer agents.