Figure 1.

The primary tumor microenvironment. Cancer cells in primary tumor are surrounded by a complex microenvironment including multiple stromal cell types that converge to promote tumor growth and dormancy, invasion and metastasis development and resistance to therapy. Key role of bone-marrow derived mesenchymal stem cells (BM-MSCs) in tumor cell migration and invasion. Cancer stem cell (CSC); carcinoma associated fibroblasts (CAFs); dendritic cell (DC); myeloid-derived-suppressor cells (MDSCs); natural killer (NK); tumor associated macrophages (TAM).