However, Tang et al. used patient samples from O’Rourke’s phase I clinical study46 and demonstrated a positive association between PD-1 expression and peripheral engraftment of EGFRvIII-CAR-T cells, as well as improved progression-free survival.74 Thus, more studies are needed to clarify the effects of PD-1 and its potential role in mediating CAR-T effectiveness in GBM. The gene discussed is PDCD1; the disease is glioblastoma.