In some hepatocellular carcinoma cell lines, intracellular only, but not secreted OPN, was expressed while its overexpression was capable of inducing MET features, through the upregulation of E-cadherin and the decrease of mesenchymal markers such as vimentin, N-cadherin, alpha-smooth muscle actin (α-SMA), ZEB1 and ZEB2. The gene discussed is SPP1; the disease is hepatocellular carcinoma.