Data mining from The Cancer Genome Atlas (TCGA) dataset for breast cancer showed significant overexpression of CDCA2 in some subtypes of breast cancer, which were Erb-B2 Receptor Tyrosine Kinase 2/Estrogen receptor/progesterone receptor (ERBB2/ER/PR) negative (triple-negative breast cancer [TNBC]), invasive ductal breast carcinoma, invasive breast carcinoma, and invasive lobular breast carcinoma. The gene discussed is PGR; the disease is triple-negative breast carcinoma.