Some embodiments of the methods and compositions provided herein include cells having membrane-tethered, IL13 mutein-directed zetakine receptors, such as those which specifically bind to the IL-13 receptor alpha 2 (IL13Ra2) at a 50-fold higher affinity than wildtype IL-13, and methods of cell-based immunotherapy targeting cancer cells, such as cells of solid tumors, using these compositions. In some embodiments, the receptors include spacer regions, such as particular spacer regions designed to provide certain advantages.