Interestingly, frequencies of double negative (DN) B cells (IgD-CD27-), which have been shown to be associated with immune senescence [10], exhaustion [5] and autoimmunity [32], were significantly higher in the young HIV compared to young HC; and also were higher in old HC compared to young HC groups suggesting that this subset may play an inhibitory role in B cell response to vaccination. The gene discussed is CD27; the disease is Autoimmunity.