CD274 and oropharynx squamous cell carcinoma: Recent studies about oropharyngeal squamous cell carcinomas and cervical cancer of the uterus indicate that PD-L1 expression is related to HPV status, suggesting that PD-L1 expression is increased in HPV-associated carcinomas (Mezache et al. 2015, 2017; Badoual et al. 2013; Lyford-Pike et al. 2013).