PDCD1 and skin squamous cell carcinoma: While previous studies have evaluated the role of PD-L1 in high risk skin squamous cell carcinomas, none have described their colocalization with CD8+ T-cells in high risk cSCC.27, 28, 29, 30 In this study, a higher chance of recurrence was demonstrated in patients who exhibited co-localization of PD-1/PD-L1 > 3.3%, although this value did not reach statistical significance; nevertheless, we observed a statistical trend.