In 2011, Robert Manguso was working in a cell biology lab when his mother was diagnosed with Merkel cell carcinoma, a rare and aggressive skin cancer. Manguso, who’d recently graduated from college and was conducting research at the University of Copenhagen as a Fulbright scholar, moved back to the Boston area to be with his mother as she underwent treatment. He also read everything he could about her disease, including emerging evidence that suggested that the immune system could recognize and kill Merkel cell carcinoma. His mother had a presentation of the disease that suggested her immune system was already on the job. But immunotherapy was not yet widely used and had not been applied clinically to Merkel cell carcinoma, so she received traditional chemotherapy and radiation therapy, suffering life-threatening complications along the way. Though the treatment eliminated her cancer, Manguso was struck by the promise of immunotherapy, which offered the potential to harness the immune system to fight cancer without the harsh side effects his mother had experienced. As he searched for graduate school programs that same year, Manguso decided to move away from his interest in fundamental cell biology and focus instead on cancer immunotherapy.