Such tumour-produced molecules, including IL-4, IL-6, IL-10, CSF-1, TGFβ and prostaglandin E2 (PGE2), and TAM-produced factors such as IL-10 and PGE2, contribute to the general immunosuppression of the host as well as the antitumour activity of macrophages (Elgert et al, 1998; Mytar et al, 2003). Here, IL4 is linked to neoplasm.