Abstract: Provided herein are CD70-binding proteins comprising a CD70-binding domain and a transmembrane domain, engineered immune cells comprising the CD70-binding proteins, and methods of making and using the same. Also provided herein are engineered immune cells e.g. CAR (chimeric antigen receptor) T cells for administration to patients to treat cancer (e.g., solid tumors and hematologic tumors) and other unwanted conditions. The cells are engineered to functionally express a first antigen binding molecule e.g. a CD70 CAR and a second antigen binding molecule e.g. a second CAR that binds a target molecule characteristic of the cancer or other disease or unwanted condition. The cells may be further engineered to reduce the functional expression level of one or more of TRAC, CD52 and CD70. Also provided are methods of making and using the engineered cells, compositions and kits comprising them, and methods of treating by administering them.