CD274 and head and neck cancer: The difference might be attributed to the inclusion of both PD‐L1 positive and PD‐L1 negative patients.32, 33, 34 In a phase III study, KEYNOTE‐040, the survival results also showed that pembrolizumab provided a clinically meaningful prolongation of OS, but not PFS, compared with standard‐of‐care in patients with recurrent or metastatic head and neck cancer (OS: HR 0.80, 95% CI: 0.65‐0.98, P = .0161; PFS: HR 0.96, 95% CI: 0.79‐1.16, P = .33).35