CD274 and head and neck squamous cell carcinoma: A single-center clinical trial demonstrated that additional use of nimotuzumab (anti-EGFR) could benefit advanced HPSCCa patient population with tolerable toxicity, but two multicenter clinical trials of avelumab (anti-PD-L1) and lapatinib (EGFR/ErbB2 inhibitor) in the HNSCC patient population, respectively, showed opposite results [42–44].