Panjwani PK, et al. - The goal of this paper was to assess the expression of programmed death (PD-1) ligand and PD-L2 proteins using immunohistochemistry in diagnostic lymphoma biopsies. The yielded data affirmed and extended prior studies of PD-L1, and provided new findings in terms of PD-L2 expression in lymphomas. It was reported that the differential expression patterns in some tumor types and the expression of PD-L2 in the absence of PD-L1, raised the possibility of targeted therapy for additional subsets of patients with lymphoma.