Bessler et al. demonstrated that there was a reduction of IL-10 levels in lymphocyte cultures from B-CLL patients [131], while other authors reported that serum IL-10 levels were increased in B-CLL patients, which may operate as an element to extend the lifespan B-CLL lymphocytes in vivo [96]. The gene discussed is IL10; the disease is B-cell chronic lymphocytic leukemia.