Mara Aspinall is president of Ventana Medical Systems (Tucson, Arizona), a maker of tissue-based cancer diagnostics and a member of the Roche Group. Prior to joining Ventana in September 2011, she was founder, president, and CEO of On-Q-ity, a start-up diagnostics company focused on circulating tumor cell technology. Prior to that, Aspinall spent 12 years with Genzyme, where she held senior leadership roles such as president of Genzyme Genetics and president of Genzyme Pharmaceuticals.