MKI67 and neoplasm: Neoadjuvant single-agent gefitinib and gefitinib combined with the AIs anastrozole effectively reduced the size of breast tumours and levels of ER phosphorylation in previously untreated patients with ER/EGFR positive disease, with the combination treatment outperforming gefitinib alone in terms of reduction in tumour proliferation rate as measured by Ki67 (Polychronis et al, 2005).