A small-molecule inhibitor of several kinases with potential antineoplastic activity. Multikinase inhibitor AT9283 binds to and inhibits Aurora kinases A and B, JAK2 (Janus kinase 2) and the kinase BCR-ABL, which may result in the inhibition of cellular division and proliferation and the induction of apoptosis in tumor cells that overexpress these kinases. Aurora kinases are serine-threonine kinases that play essential roles in mitotic checkpoint control during mitosis; JAK2 is a kinase that transduces signals from the single chain and IL-3 cytokine receptor families, and from the IFN-gamma receptors; BCR-ABL is a fusion protein with tyrosine kinase activity that is commonly found in CML.