For the first time, Mishra et al. (2008) observed that the effect of prolonged exposure of MSCs to factors produced by a human breast cancer cell line MDA-MB-231 caused up-regulation of 53 CAF-associated genes and an higher expression of α smooth muscle actin (α-SMA), vimentin, fibroblast surface protein (FSP) and SDF-1 [2]. Here, CXCL1 is linked to breast cancer.