Combination chemotherapy with PD-1 inhibition has emerged as a promising approach for patients with NSCLC, gastric, and, to a lesser extent, HNSCC.2–6 However, similar benefit from combining chemotherapy with immunotherapy has not been demonstrated in other malignancies.6 The toxicity profile observed from the combination of chemotherapy and immunotherapy underscores the continued need for safer combination regimens with improved tolerability. This evidence concerns the gene PDCD1 and head and neck squamous cell carcinoma.