PDCD1 and neoplasm: Other genes in this region encompass JAK2, PDL2, and JMJD2C, the upregulation of all of which seems to be vital for HRS cells (30), explaining why blocking PD1 might be more effective than blocking PDL1 in cHL as the first might prevent the tumor cells also from relying on PDL2 as a substitute of blocked PDL1 (31).