Figure 1.

Breast tumor microenvironment. This figure offers a comprehensive view of the complex processes at play during breast cancer progression. The breast cancer TME represents a dynamic landscape crucial to understanding cancer progression. At the start of tumor formation, immune responses from cytotoxic T lymphocytes, M1 macrophages, and fibroblasts try to suppress tumor growth. However, breast cancer cells adapt and educate neighboring stroma cells to support their growth. Key players, such as cancer-associated fibroblasts (CAFs), are activated via cytokines, leading to the secretion of factors that support tumor development. Tumor-associated macrophages (M2 macrophages) also play a role by releasing pro-tumorigenic factors. As the tumor expands, it recruits regulatory T cells and other immune cells that hinder the immune response. All these orchestrated events within the TME contribute to breast cancer cells’ gaining mobility, invasiveness, and the ability to spread to secondary sites.