The induction of senescence in human mammary fibroblasts by KDM2A triggers senescence-associated secretary phenotype, which is accompanied with the release of a number of cytokines including IL-6, IL-8, CXCL1 etc. These cytokines reciprocally stimulate the proliferation of breast cancer cells as evidenced by the increase of cancer cell growth by the conditioned medium of KDM2A-overexpressing fibroblasts (Fig. S3). Here, CXCL8 is linked to breast cancer.