ROR1 and cancer: We next applied BEHAV3D to evaluate two alternative T cell immunotherapy concepts: (1) T cells engineered with a conventional αβ TCR that targets tumor cells through recognition of the cancer-specific Wilms tumor antigen-1 (WT1) peptide presented on HLA-A*0201 (ref. 30), and (2) T cells engineered to express a CAR targeting the tumor-expressed receptor tyrosine kinase-like orphan receptor 1 (ROR1) antigen4.