Furthermore, Farmer et al. [17] proposed a new classification of breast cancer subtypes based on ERα and AR status: luminal disease positive for both receptors (ERα+/AR+), basal disease negative for both receptors (ERα−/AR−) and molecular apocrine disease with ERα negative and AR positive staining, showing similar characteristics to those of the normal apocrine glands. This evidence concerns the gene ESR1 and glycogen storage disease VI.