More than a decade ago, doctors at the University of Pennsylvania treated a patient with her own T cells, which had been engineered to recognize and target the cancer cells in her body. The treatment, which is called CAR T cell immunotherapy, is now widely used for patients with leukemia, lymphoma, and myeloma. Today, scientists like Saul Priceman are working to take this therapy to the next level, making it effective against as many cancer types as possible. He talked with Chuck and Alicia about what his lab is doing to improve CAR T cell immunotherapy.