To achieve this, we co-cultured tumor cells expressing the PD-L1WT or different PD-L1 variants with IcAR-PD-1 cells in the presence and absence of increasing concentrations (1.5 μg/mL to 40 μg/mL) of FDA-approved anti-PD-1 antibodies: Pembrolizumab [38], Nivolumab [39], and Cemiplimab [39]; these antibodies bind well to PD-1 on IcAR-PD-1 cells (Supplementary Fig. 3A). Here, PDCD1 is linked to neoplasm.