Of note, Dilly‐Feldis et al30 reported a transition from initially negative to positive PD1 labeling of intra‐tumoral lymphocytes in five of nine relapsed/refractory cases of pediatric classical Hodgkin's lymphoma (cHL) and a trend toward a more intense PD‐L1 staining of tumor cells at relapse. Here, CD274 is linked to classic Hodgkin lymphoma.