Genomic analyses have subclassified breast cancer into 4 categories: luminal A (ER+ and/or PR+, HER2-); luminal B (ER+ and/or PR+, HER2+); HER2+ (ER-, PR-); and basal-like (ER-, PR-, HER2-) [54]. The gene discussed is PGR; the disease is breast carcinoma.