BCR and B-cell non-Hodgkin lymphoma: To study the role of the BCR complex in supporting the growth of B‐cell lymphomas, we used the CRISPR/Cas9 gene‐editing tool to generate Ramos B‐cell mutants lacking all (BCR‐null) or some of the four BCR components, H and L chains, Igα and Igβ, (Fig 1A).