PD-1/PD-L1 expression in thymic epithelial tumors: the predicament persists

This editorial is based on the article titled “Expression patterns, prognostic value, and intratumoral heterogeneity of PD-L1 and PD-1 in thymoma and thymic carcinoma” recently published in Journal of Thoracic Oncology, where thymic epithelial tumors (TET) have shown increased expression of immune checkpoint inhibitors: programmed death 1 (PD-1) and its ligand PD-L1 (1).