CD274 and head and neck squamous cell carcinoma: Lupu‐Plesu et al. recently published results of an in vitro study in head and neck squamous cell carcinoma cells examining the biological effects of proton versus photon RT for genes involved in anti‐tumor autoimmunity, namely PD‐L1, and found that both proton and photon RT augment PD‐L1 mRNA expression in a dose‐dependent manner.17 Given our limited cohort size, this question should be addressed in future larger studies since no conclusion can be drawn at this time.