Although the results in some clinical studies of RCC [15], HPV-positive HNSCC [13], and melanoma receiving anti-PD-1 after recurrence [16] showed that TMB alone also did not clearly distinguish responders and predict OS, it is still exciting that multiple studies in the 2020 American Society of Clinical Oncology (ASCO) meeting have confirmed the predictive value of TMB in immunization or combination therapy (KEYNOTE-061 study [17, 18], CONDOR study [19], EAGLE study [20], EPOC1704 study [21], etc.), consolidating its status of TMB as an independent predictor. Here, PDCD1 is linked to head and neck squamous cell carcinoma.