MET and neoplasm: These cells showed elevated expression of ATP-binding cassette (ABC) transporter ABCG2, as well as proto-oncogenes including c-MET and AKT, the epithelial-to-mesenchymal transition marker N-cadherin, and the tumour-initiating cell surface marker aldehyde dehydrogenase (ALDH) both in vitro and in vivo (Supplementary Figs 1c,d and 2).