Figure 2.

Recruitment of distant (BM)/resident MSCs, activation via diverse mechanisms, and differentiation to CAFs of the TME. Perivascular cells (MSCs/fibroblasts) as well as pericytes (blue) are resident cells, while MSCs from the bone marrow can be recruited in tumor sites. Factors derived mainly from necrotic tissues (notably in response to therapies) and infiltrating immune cells such as macrophages may contribute to the recruitment, proliferation, and activation of MSCs/Fib. MSCs will differentiate into CAFs with either restraining or promoting activities towards cancer cells. (Figure designed by BioRender).