IL6 and cancer: Indeed, treatment of normal RMF-EG fibroblasts with IL-6 and TNF-α, two abundant cytokines in the conditioned medium of MDA-MB-231 cancer cells,18 increased KDM2A protein level in a dose-dependent manner suggesting these two cytokines may play a role in stimulating KDM2A expression in fibroblasts (Fig. 2b, c).