BTK and B-cell non-Hodgkin lymphoma: There was no significant relationship between severe disease and B‐cell lymphoma related risk factors, such as subtypes, B symptoms, Eastern Cooperative oncology Group (ECOG) performance status, disease stage, extranodal involvement, lactate dehydrogenase (LDH) level, previous response status, and previous autologous hematopoietic stem cell transplantation (ASCT) at the time of CAR‐T infusion, as well as prior use of bendamustine and Bruton's tyrosine kinase (BTK) inhibitors, the data were presented in Table 2.