Particularly noteworthy is also the fact that ki-67 staining is related to overall survival in breast cancer patients and that several clinical applications are integrated within the standard routine: On the one hand, ki-67 is used to define the intrinsic subtype (luminal A / luminal B tumors) of breast cancer; on the other hand, it can be used (together with other parameters) for risk assessment and identification of patients who benefit from chemotherapeutical treatment in addition to endocrine therapy. The gene discussed is MKI67; the disease is breast cancer.