The remaining cases have other special subtype carcinomas.11 Molecular classification immunohistochemically categorizes breast cancer into four subtypes in terms of the expression of hormone receptors: estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), human epidermal growth factor receptor 2-positive (HER2+), and triple-negative breast cancer.12 The gene discussed is PGR; the disease is triple-negative breast carcinoma.