MKI67 and breast cancer: In the latter case, the Ki-67 cut-off was fine-tuned against gene expression profiling in order to distinguish Luminal A from Luminal B tumors in a population containing both high- and low-risk breast cancers, whereas in the neoadjuvant setting the same cut-off was intended to identify the majority of, mainly high-risk, patients that would most likely benefit from preoperative cytotoxic therapy.