CD8A and breast cancer: Coincubation of E0771 mouse breast cancer cell line, which stably expresses human HER2 antigen (E0771-hHER2), with hHER2-CAR expressing mouse CD8 T cells induced dramatic cytotoxicity compared to the control CD8 T cells (Supplementary Figures 1C-E), confirming that HER2-CAR expression redirects CD8 T cells to eliminate HER2-expressing target cells.