Further, we observed increased IL4 activity within CLL‐infiltrated lymph nodes compared with tumour‐free lymph nodes, which complements previous work demonstrating higher IL4 activity in the lymph node compared with peripheral blood (Aguilar‐Hernandez et al, 2016; Herishanu et al, 2011). The gene discussed is IL4; the disease is B-cell chronic lymphocytic leukemia.