In this study, the numbers of CD8+ TIICs and PD-1+ TIICs were comparable with those reported in a previous study that examined multiple cancer types, including ESCC.24 As CD8+ lymphocytes are activated and trafficked to the tumour from the tumour-draining lymph node via antigen-presenting cells reacting to tumour-associated antigens,25 the comparable numbers of CD8+ TIICs among the three locations indicate that the immune system of the host responded similarly regardless of the location in the primary tumour. The gene discussed is CD8A; the disease is esophageal squamous cell carcinoma.