All tumours express antigens that can be recognised by the immune system, but in most cases an inadequate immune response is elicited because of ineffective activation of effector cells by downregulation of major histocompatibility (MHC) molecules or inhibition of their function by factors produced by the tumour, such as TGF-β or IL-10 (Cheng et al, 2004; Houghton and Guevara-Patino, 2004; Campoli et al, 2005). This evidence concerns the gene IL10 and neoplasm.