de Vicente JC, et al. - Researchers assessed the clinical and prognostic value of PD-L1 in oral squamous cell carcinoma (OSCC). They used PD-1 immunostaining and two different commercially available PD-L1 antibodies (clones E1L3N and 22C3) to stain tissue microarrays of 125 resected OSCC. They observed a link between PD-L1 expression in more than 10% of tumor cells and poorer survival, which was established as a clinically relevant cut-off point. Based on the anti-PD-L1 antibody, they noted this relevant PD-L1 expression in 10% to 15% OSCC specimens. It was inversely correlated with tobacco and alcohol consumption. Tumor recurrence and lower disease-specific survival were reported consistently in association with PD-L1 expression. In multivariate analysis, neck node metastasis and tumor PD-L1 expression were further identified as significant independent factors for poor prognosis.