In a multicenter single arm study that included 60 patients with R/R MCL who had received a bruton tyrosine kinase (BTK) inhibitor, anthracycline‐ or bendamustine‐based chemotherapy, and CD 20 monoclonal antibody, impressive results were seen in patients who received a single dose of brexu‐cel with reported 93% ORR and 67% CR rate in this study. This evidence concerns the gene BTK and mantle cell lymphoma.