It is also worth noticing that there are several risk factors that increase a BC patient’s probability to develop brain metastases, including younger age, ductal histology, increased tumor size, nodal metastases, lung and liver metastases, higher tumor grade, overexpression of epidermal growth factor receptor (EGFR), mutations in the BRCA1 gene and the overexpression of Ki-67. Here, MKI67 is linked to neoplasm.