Figure 1.

Composition of the tumor microenvironment (TME) in breast cancer. The breast cancer microenvironment is composed by a variety of immune cells, including a huge proportion of suppressive cells, such as M2 macrophages, regulatory T cells, and myeloid-derived suppressor cells that ultimately induce the secretion of proinflammatory mediators to promote the development and progression of cancer cells. However, the TME also includes a low proportion of dendritic cells and tumor-infiltrating lymphocytes, such as T, B, and Natural Killer cells. In this sense, immunotherapies have shown to boost the maturation and function of those cells to exert potent immune responses against the tumor.