BCR and mantle cell lymphoma: Treatment with novel B‐cell receptor (BCR) signalling inhibitors results in high response rates and long progression-free survival (PFS) in patients with various B‐cell malignancies, such as chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and Waldenström’s macroglobulinemia (WM) [1].