Intriguingly, although most MCAs of the breast exhibit immunohistochemical negativity for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), they generally present with a significantly more favorable prognosis compared to conventional basal-like triple-negative breast cancers (Joneja & Palazzo, 2023; Lei, Shi & Chen, 2023; Moatasim & Mamoon, 2022). The gene discussed is PGR; the disease is triple-negative breast carcinoma.