PTEN and neoplasm: BT474 tumours excised at week 12 from Figure 1B were lysed and analysed by western blotting to detect tyrosine-phosphorylated ErbB-2 (PY1248), total ErbB-2, phosphorylated ERK1/2, total ERK1/2, phosphorylated AKT1, total AKT1, and PTEN proteins.