The breast cancer tumor microenvironment (TME) is a dynamic and complex ecosystem that plays a crucial role in tumor progression, immune evasion, and resistance to anti-tumor therapies. The TME comprises various immune and non-immune cells, including cancer cells, stromal cells, vasculature, and infiltrating immune cells. These cells exhibit phenotypic and functional plasticity, contributing to both pro-tumor and anti-tumor roles during tumor progression. Key components of the TME, such as myeloid-derived suppressor cells (MDSCs), tumor-associated neutrophils (TANs), mast cells (MCs), tumor-associated macrophages (TAMs), dendritic cells (DCs), natural killer (NK) cells, and B lymphocytes, have been extensively studied for their roles in immune suppression, angiogenesis, and immune evasion. Recent advances in understanding the multifaceted nature of the TME have led to the development of novel therapeutic strategies, including targeting specific TME components to enhance anti-tumor immunity and improve patient outcomes. However, the complexity of the TME and its impact on immune evasion necessitate further research to develop more effective and safe treatments for breast cancer.The breast cancer tumor microenvironment (TME) is a dynamic and complex ecosystem that plays a crucial role in tumor progression, immune evasion, and resistance to anti-tumor therapies. The TME comprises various immune and non-immune cells, including cancer cells, stromal cells, vasculature, and infiltrating immune cells. These cells exhibit phenotypic and functional plasticity, contributing to both pro-tumor and anti-tumor roles during tumor progression. Key components of the TME, such as myeloid-derived suppressor cells (MDSCs), tumor-associated neutrophils (TANs), mast cells (MCs), tumor-associated macrophages (TAMs), dendritic cells (DCs), natural killer (NK) cells, and B lymphocytes, have been extensively studied for their roles in immune suppression, angiogenesis, and immune evasion. Recent advances in understanding the multifaceted nature of the TME have led to the development of novel therapeutic strategies, including targeting specific TME components to enhance anti-tumor immunity and improve patient outcomes. However, the complexity of the TME and its impact on immune evasion necessitate further research to develop more effective and safe treatments for breast cancer.