HDAC9 and diffuse large B-cell lymphoma: At the last follow-up, the patient remains in radiographic CR 22 months after CAR-T infusion and 10 months after the initiation of the combination treatment.<h4>Conclusion</h4>We report the first successful case of dual inhibition of HDAC and BTK for the treatment of R/R DLBCL after failure to CAR-T cell therapy, which opens a new therapeutic possibility for the future.