It is reported that less immunogenic cancer cells are selected for during tumour development in immune-competent hosts to evade antitumor immune responses (Dunn et al., 2002), which may result in increased immunosuppressive cells (e.g., regulatory T cells and TAMs) and expression of immunosuppressive molecules (e.g., CTLA4 and PD1). This evidence concerns the gene CTLA4 and neoplasm.