CD274 and classic Hodgkin lymphoma: A genetic base for the enhanced PD-L1/PD-1 signalling is extremely rare among neoplasms and could at least partially explain the impressive overall response rate (about 70%) to the PD-1 blockade by monoclonal anti-PD1 antibodies (nivolumab and pembrolizumab, Table 1) observed in relapsed and refractory cHL patients [14,15].