While clinical trials have indicated a synergistic effect of cetuximab plus a PD-1 inhibitor compared to PD-1 inhibitor monotherapy in recurrent or metastatic HNSCC, Zhang et al.’s meta-analysis reveals that this combination therapy is likely effective in improving response rate and 1-year overall survival only in HPV(−) patients [89]. Here, PDCD1 is linked to head and neck squamous cell carcinoma.