BTK and mantle cell lymphoma: Identifying MCL patients at increased risk for relapse after HDCT/Auto-HSCT is of growing importance as novel therapeutic options, including bruton tyrosine kinase (BTK) inhibitors, immunomodulatory agents and chimeric antigen receptor (CAR) T cell therapies have improved the prognosis of MCL patients relapsing after HDCT/Auto-HSCT and might even challenge the status of HDCT as standard frontline treatment in the future [33,34,35,36,41].