Our results were consistent with previous study which found S100‐A9 protein in exosomes from chronic lymphocytic leukaemia cells promotes NF‐kB activity.53 We also found exosome‐enriched S100‐A9 disturbed steroidogenesis by deregulation of CYP17 mRNA expression via NF‐κB pathway‐dependent manner. The gene discussed is S100A9; the disease is B-cell chronic lymphocytic leukemia.