Alex Kentsis is a pediatric oncologist and cancer biologist. He directs the Tow Center for Developmental Oncology at the Memorial Sloan Kettering Cancer Center, where his research takes advantage of modern technologies to improve our understanding of the biologic causes of leukemias. Together with colleagues, he has made discoveries about new therapeutic targets in cancer cells, mechanisms by which cancer cells can evade new treatments, and improved strategies to overcome treatment resistance. Recently, his lab has identified new mechanisms of aberrant gene control and resistance to apoptosis in acute myeloid leukemias, and mechanisms of site-specific oncogenic mutations and DNA repair dependencies in human cancers. Combined with the development of new functional proteomic methods and therapeutics, this work is now poised to define precise molecular mechanisms that would lead to rational therapeutic strategies for patients.