Figure 2.

Role of the cancer stem cells in the development of the tumor microenvironment. Cancer progression is generated and sustained by several factors, such as epigenetic forces, somatic mutations, and EMT. On the other hand, these events lead to the generation of distinct cancer stem cell clones inside the cancer moiety, and enrich the cancer stem cell niche. During the late stages of tumor progression these stem cell clones sustain the cancer expansion with their self-renewal ability. Thus, the cancer stem cell niche can also be regarded as a reservoir of self-sustaining cells for the tumor microenvironment.