Another interesting activity of cadmium was demonstrated by Liu et al. Their results showed that in MCF-7 cells, a relatively benign breast cancer cell line, cadmium rapidly activated extracellular signal-regulated kinase 1 and 2 (ERK1/2), AKT, and ERα at a micromolar concentration within 2.5 min. This evidence concerns the gene ESR1 and breast carcinoma.