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. This evidence concerns the gene CYP17A1 and B-cell chronic lymphocytic leukemia.