This issue was recently noted by Miyoshi et al and Asano et al among patients with ATLL.47, 48 Some clinical trials have reported that the tumor microenvironment generally correlates with higher response rates to anti‐PD‐1/PD‐L1 therapies.22, 49 However, the administration of immunotherapy against the PD‐1/PD‐L1 pathway for iDLBCL with high PD‐L1 expression in the microenvironment may be considered carefully due to their extremely favorable outcome, with the exception of CD5+, EBV+, and nPD‐L1+ cases. Here, CD5 is linked to neoplasm.