MKI67 and breast cancer: The luminal subtype can be further divided into luminal A (low Ki-67 expression) and luminal B (high Ki-67 expression) based on Ki-67 levels.[6,7] TNBC is more frequently observed in younger patients and is typically associated with larger tumor size, higher grade, and a greater likelihood of lymph node involvement at diagnosis, demonstrating increased biological aggressiveness.[8] Women with TNBC also experience higher early distant recurrence rates and worse five-year survival outcomes than those with other breast cancer subtypes.[8,9]