Immunotherapies that fight cancer have been a life-saving advancement for many patients, but the approach only works on a few types of malignancies, leaving few treatment options for most cancer patients with solid tumors. Now, in two related papers published April 28, 2021, in Science Translational Medicine, researchers at UCSF have demonstrated how to engineer smart immune cells that are effective against solid tumors, opening the door to treating a variety of cancers that have long been untouchable with immunotherapies.