**Abstract**

Stromal cells are stem cells in the bone marrow microenvironment that can 'talk' with neighbouring and distant cells within the bone marrow microenvironment. Stromal cells propagate this intercellular communication via cytokines, growth factors as well as small extracellular vesicles. The interaction between stromal cells and the haematopoietic stem cells, is crucial in the regulation of haematopoiesis. Aberration in this regulatory process will lead to the development of various diseases, including cancer. These stromal cells also play important role in the patient's response to cancer therapy. As a result, these stromal cells may be crucial in the development and metastasis of cancer within the bone marrow microenvironment. In this chapter, we will explore the role of these stromal cells in carcinogenesis and cancer metastasis.

**Keywords:** stromal cells, extracellular vesicles, cancer, metastasis, tumour, microenvironment, bone marrow, therapy
