PDCD1 and cancer: While exhaustion the role of Programmed Cell Death 1 (PD-1/CD279), Hepatitis A Virus Cellular Receptor 2 (TIM3/HAVCR2), Lymphocyte Activating 3 (LAG3) and other checkpoint molecules has been less studied in γδ T cells compared to conventional αβ T cells (59), the low to absent PD-L1 expression on cancer organoids may favour persistent effector activity of γδ T cells.