It is believed that the release of proinflammatory Th1 cytokines such as interferon-γ (INF-γ) may contribute to antitumour and antimicrobial functions while that of immunomodulatory Th2-cytokines such as interleukin 4 (IL-4) may help alleviate autoimmune diseases5 such as multiple sclerosis6 (MS) and arthritis.7 Here, IL4 is linked to myeloid sarcoma.