BTK and diffuse large B-cell lymphoma: This has facilitated the development of new targeted therapies for DLBCL-related pathways and molecular targets, including immunosuppressive agents, Bruton’s tyrosine kinase (BTK) inhibitors and chimeric antigen receptor T-cell products, which offer new treatment options.[2–4] However, while new drugs are improving patient outcomes, infections are a significant problem and the incidence of opportunistic infections after immunosuppression is increasing.