After co-culture with the different cancer cell lines, reactivity (assessed by expression of activation markers and secretion of IFNγ) was largely restricted to PD-1+ γδ T cells (Vδ1 or Vδ3+), whereas activation of PD-1– γδ T cells (Vδ2+) was generally not detected (Fig. 3c and Extended Data Fig. 4). The gene discussed is PDCD1; the disease is cancer.