PDCD1 and Hodgkins lymphoma: In phase I/II clinical trials with nivolumab and pembrolizumab (humanized immunoglobulin G4 monoclonal antibodies targeting PD-1) in patients with relapsed and refractory classic HL (r/r cHL), the overall response rates (ORRs) were between 58% and 87%, with 12%–45% of patients achieving complete remission (CR) (Ansell et al., 2015; Armand et al., 2016; Younes et al., 2016; Chen et al., 2017; Armand et al., 2018; Chen et al., 2019; Bekoz et al., 2020).