CAR T cells are genetically engineered immune cells that have been very successful in the treatment of certain blood cancers, but their use in solid tumors (solid tumors) has been problematic until now[1]. A major problem is that solid tumors do not have a single, universally shared surface target for CAR T cells to target[1]. Scientists have discovered that the CD70 protein is heterogeneously expressed in many solid tumors – some cancer cells have it in abundance, while others have it in minimal amounts[1]. The research team developed an ultra-sensitive receptor called HIT receptor (HLA-independent T cell receptor), which can detect even very low levels of CD70[1]. In preclinical models, CD70-HIT cells completely and permanently cleared kidney, ovarian, and pancreatic tumors, even when these tumors showed mixed levels of CD70[1]. The authors found that CD70 is expressed heterogeneously in twenty or more types of solid tumors[1]. These findings suggest that CD70 could be a universal target for the treatment of a wide range of solid tumors using ultra-sensitive CAR T cells[1].