Patient-derived mammosphere and xenograft tumour initiation correlates with progression to metastasis. by Eyre, R, Alférez, D, Spence, K, Kamal, M, Shaw, F, Simões, B, Santiago-Gómez, A, Sarmiento-Castro, A, Bramley, M, Absar, M, Saad, Z, Chatterjee, S, Kirwan, C, Gandhi, A, Armstrong, A, Wardley, A, O'Brien, C, Farnie, G, Howell, S, Clarke, R