Tumor microenvironment contribution to checkpoint blockade therapy. Lessons learned from Hodgkin lymphoma.

Classic Hodgkin lymphoma (cHL) is characterized by a tumor microenvironment (TME) containing inflammatory/immune cells. Follicular lymphoma, mediastinal grey zone lymphoma and diffuse large B-cell lymphomas, may show a TME containing inflammatory/immune cells, but the TMEs are quite different. In these B-cell lymphomas and cHL, PD-1/PD-L1 blockade drugs differ in their effectiveness in patients with refractory/relapsed disease. Research should still explore innovative assays that could reveal which molecules are influencing the sensitivity or the resistance to therapy in an individual patient.