GRP78.ΔCAR T cells co-cultured with cell surface GRP78+ MOLM13 cells (Supplementary Fig. 6a–c) did not exhibit any antitumor activity, confirming that cell surface GRP78 binding alone is insufficient to induce tumor cell death (Ctrl CAR vs GRP78.ΔCAR, p = NS). Here, HSPA5 is linked to neoplasm.