As an example, Roodhardt et al. described an induction of cancer cell chemoresistance by the MSCs through the release of a fatty acid while Castells et al. propose that chemoresistance could be acquired by cancer cells through release of IL-6 and IL-8 by macrophages which were activated by an unidentified secreted factor produced by MSCs in human ovarian cancers [4]. Here, IL6 is linked to ovarian cancer.