TFRC and neoplasm: In anti-Her2 CAR T cells engaging Her2+ tumor cells, PCC between CAR and TCR in the synapse was not different from the TfR negative control (mean PCCCAR_TCR = 0.149; PCCCAR_TfR = 0.040), while the GFP-CAR signal showed a strong correlation with the anti−CAR antibody as positive control signal (mean PCCCAR_CAR = 0.628) (Figure 4H).