MLN-8237 is a second-generation, selective Aurora A kinase (AAK) inhibitor with an IC50 of 1 nM. MLN8237 shows 200-fold more selective activity against Aurora-A than related kinase Aurora-B. Inhibition of AAK by MLN-8237 induces cytotoxicity and cell arrest. Several completed as well as actively on-going phase I/II clinical trials evaluate MLN-8237 in advanced solid tumor as well as advanced hematological malignancies.