Our results indicate that EDCs, such as BPA, BPAF, or Zea, are not only able to act as ER agonists but also as antagonists, with effects that are dose- and cell-dependent; this supports the results of experimental studies on insulin secretion and obesity (Hugo et al. 2008; Makaji et al. 2011). The gene discussed is ESR1; the disease is obesity due to melanocortin 4 receptor deficiency.