The preliminary results of the single-arm, open-label, multicenter, phase II BGB‐3111‐215 study conducted in patients with R/R B-cell malignancies (CLL/SLL, MCL, MZL, or WM; N = 64) who were intolerant to previous BTK inhibitors (ibrutinib and acalabrutinib) showed good efficacy and tolerability to treatment with zanubrutinib. This evidence concerns the gene BTK and marginal zone lymphoma.