Two recent reports have investigated checkpoint inhibitor expression on T cells within the TIL of SCCHN patients.21, 22 In particular, these manuscripts show an upregulation of PD-1 and CTLA-4 within the TME on T cells compared with PBL, although neither of these articles investigated OX40 expression. Here, TNFRSF4 is linked to head and neck squamous cell carcinoma.