CD19 and neoplasm: To determine if the activation of the CTM + 12EC, CTM + 39EC, and CTM + 41EC constructs seen in the presence of recombinant PD-L1 could be reiterated with PD-L1+ tumour cells, we cocultured transduced T cells with either wild-type (WT) or PD-L1+ Nalm-6 tumour cells that bear an identical expression of CD19 (Supplementary Fig. 2A,  B).