MLN8054 is a selective inhibitor of Aurora A kinase, an enzyme involved in cell division and mitotic regulation. It has been primarily investigated for its potential in cancer therapy, particularly in tumors that rely on aberrant mitotic signaling for growth and survival. By inhibiting Aurora A kinase, MLN8054 disrupts proper spindle formation during mitosis, leading to cell cycle arrest and apoptosis in rapidly dividing cancer cells. The compound has shown activity in preclinical models of various solid tumors and hematologic malignancies, including neuroblastoma, melanoma, and certain types of lymphoma. Its selectivity for Aurora A over Aurora B helps reduce off-target effects, potentially improving the therapeutic window. MLN8054 has also been studied in combination with other chemotherapeutic agents to enhance antitumor efficacy and overcome drug resistance. Although clinical development has been limited due to pharmacokinetic challenges and the emergence of more potent analogs, MLN8054 remains a valuable tool compound for studying Aurora A kinase biology and validating this target in oncology drug discovery.