Sangaletti et al. showed that NETs, through their interaction with CD5+ B cells, drive the progression from autoimmunity to lymphoma in a mouse model of B‐cell chronic lymphocytic leukaemia. They also found that B cell–helper neutrophils release higher levels of B cell–activating and attracting factors—BAFF, APRIL, CD40L, IL‐21 and CXCL12—along with increased NET production. This evidence concerns the gene IL21 and B-cell chronic lymphocytic leukemia.