IFNG and head and neck squamous cell carcinoma: As measured by real-time impedance analysis (middle and right panels, Figure 1A–E), killing of HNSCC cells by PD-L1 CAR haNKs at low effector-to-target ratios (0.5:1 or 1:1) was significantly greater compared to haNKs in the absence of IFNγ pre-treatment of target cells.