Breast cancer is the second most common cancer in Women. Most of breast cancer related death is attributed to metastasis. The mortality rate of patients with metastatic form of the disease is extremely high because there is currently no cure for metastatic breast cancer. Thus, there is an unmet need to control this form of disease. Out of several mechanisms of metastasis progression, exosomes are thought to play an important role. Exosomes are nanovesicles that contain protein and RNA reflective of the cell type of origin. Exosomes regulate cellular communication between the primary tumor and distant organs to initiate metastasis. Exosomes form the premetastatic niche in the distant specific sites where the circulating cancer cells adhere and grow to form secondary tumors. In this project, we focused on clarifying the role of cancer derived exosomes in driving metastasis of breast cancer and to explore the potential ways to block the exosomes release in order to stop metastasis. Targeting the release of exosomes from the cells by either pharmaceutical (GW4869) or by CRISPR/Cas9 method reduced the number of exosomes secreted. The study will be beneficial in establishing a specific target and developing a treatment strategy either using a single drug or combination of multiple drugs inhibiting exosomes release along with treating the primary tumor. The project will significantly contribute in the control of disease by inhibition of the metastasis before it occurs.