PDCD1 and diffuse large B-cell lymphoma: A recent systematic review and meta‐analysis reported limited clinical benefit with immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD‐1) and its ligand (PD‐L1) or cytotoxic T‐lymphocyte‐associated protein 4 (CTLA‐4) as monotherapy in R/R DLBCL.94