Cytokines TGF-β and IL6 transform primary human mammospheres and pre-malignant mammary epithelial cell lines in vitro and make them tumorigenic in vivo (Iliopoulos et al. 2009; Nguyen et al. 2011b; Sansone et al. 2007), and inflammation-related factors COX2 and TGF-β are required for the full effect of IR on DNA damage and transformation in vitro and mammary tumor growth and invasion in vivo (Bisht et al. 2003; Nguyen et al. 2011b). Here, IL6 is linked to breast cancer.