Two antibodies targeting PD‐1, pembrolizumab (Merck & Co., Inc., Kenilworth, NJ, USA) and nivolumab (Bristol‐Myers Squibb, New York, NY, USA), have been approved for treatment of bladder cancer, renal cell carcinoma, melanoma, Hodgkin's lymphoma, non‐small‐cell lung cancer, and other tumors by the US Food and Drug Administration (FDA) since 2014 [16]. Here, PDCD1 is linked to Hodgkins lymphoma.