We confirmed the efficient retroviral transduction of T cells enriched from mouse splenocytes (Fig. 4g) and demonstrated the capacity of mouse STEAP1-mBBζ CAR T cells to induce cytolysis of the RM9 mouse prostate cancer cell line56 engineered to express human STEAP1 (RM9-hSTEAP1) by lentiviral transduction (Fig. 4h). Here, STEAP1 is linked to prostate cancer.