Recent investigations have shown that inhibitors of the ADO degrading enzyme, adenosine deaminase (ADA) were able both in IL-10−/− where they caused a decrease in Th1 cytokines (IL-1β, IFN-γ, TNF, IL-6 and CXCL10) and ameliorated the clinical and histologic score in severe colitis [120], but also in cancer patients with hairy cell leukaemia. The gene discussed is ADO; the disease is cancer.