Subtyping is based on the tumor’s hormone receptor status and can be grouped as follows: Luminal A (ER+, PR+, HER2-, KI67-), Luminal B (ER+, PR+, HER2±, KI67+), HER2 overexpression (ER-, PR-, HER2+), and Basal/Triple Negative (ER-, PR-, HER2-)[5]. This evidence concerns the gene MKI67 and neoplasm.