The tumor microenvironment refers to the complex network of cells, molecules and blood vessels that surround a tumor. This environment plays a crucial role in cancer development, growth, and metastasis. It includes various cell types such as cancer cells, immune cells, fibroblasts, endothelial cells, and pericytes, which interact with each other through secreted factors or direct contact to create an ecosystem that supports tumor progression. The tumor microenvironment also contains the extracellular matrix (ECM), a network of proteins and carbohydrates that provide structural support for cells and influence cell behavior, as well as blood vessels that supply nutrients and oxygen to the growing mass. Understanding the complex interactions within the tumor microenvironment is essential for developing new therapeutic strategies targeting cancer growth and metastasis.