Most of the current immunotherapies focus on manipulating T cells, however, the tumor microenvironment (TME) is abundantly infiltrated by a heterogeneous population of tumor-associated macrophages (TAMs) and Foxp3 + regulatory T (Treg) cells, which are supppsed to be tumor-promoting immune cells and often associated with an increased resistance to cancer therapies (Mantovani et al. 2017; Tanaka and Sakaguchi 2017). This evidence concerns the gene FOXP3 and cancer.