The results support the hypothesis that Eu reduces ATP production of cells in progression to cancer by downregulating c-Myc/PGC-1β/ERRα signaling pathway and inhibiting ROS production, as a consequence of the shift in energy metabolism toward reduced OXPHOS and FAO activity in H-ras transformed MCF10A cells, suggesting a preventive effect of Eu on energy production for rapid cell proliferation during mammary carcinogenesis (Fig. 8). Here, HRAS is linked to cancer.