PDCD1 and head and neck squamous cell carcinoma: However, unlike Hodgkin's lymphoma in which the objective response rate (ORR) is as high as 87%, the ORRs of nivolumab and pembrolizumab are only 15% for HNSCC, indicating that much more effort should be made to investigate the pattern and mechanisms of PD-1/PD-L1 expression in HNSCC (17).