This well‐known paradigm of B‐cell development has increasingly been expanded in recent years, with discoveries of alternative differentiation pathways into immunomodulatory B cells—IL‐10‐secreting B regulatory cells (Bregs)9—as well as identification of crucial B‐cell roles in diseases traditionally viewed not to involve these cells, including numerous autoimmune diseases and even cancer.10, 11. The gene discussed is IL10; the disease is cancer.