Consistent with a phase 2 trial showing that only 1 of 12 patients carrying CREBBP inactivating mutations responded to panobinostat (a HDAC inhibitor) in R/R DLBCL [24], none of the 6 patients with CREBBP inactivation mutations in this trial responded to the CR‐GemOx regimen. Here, HDAC9 is linked to diffuse large B-cell lymphoma.