However, in other types of cancer, in particular breast cancer, a higher Ki-67 index was found in lymph node metastasis than in primary tumours [42–44], suggesting greater aggressiveness of these [42] and that the use of Ki-67 in lymph node metastasis may be important in selecting the appropriate treatment for certain subgroups of patients [45]. The gene discussed is MKI67; the disease is breast carcinoma.