Sorlie et al.[11] examined the human expression profiles of 115 breast carcinomas identifying five subtypes: two hormone (oestrogen and/or progesterone) receptor-positive types (luminal-like A and luminal B) and hormone receptor-negative types [human epidermal growth factor receptor 2- overexpressing, basal-like, and unclassified (“normal-like”)]. This evidence concerns the gene PGR and breast carcinoma.