Xing W, Mai N, Dresser K, Chen BJ. PD-L1 Immunohistochemistry Highlights Bone Marrow Involvement by Classic Hodgkin Lymphoma in Staging Biopsies: Implications for Diagnosis and Tumor Microenvironment Alterations. Appl Immunohistochem Mol Morphol. 2019 May/Jun; 27(5):356-363.