Snail is a transcription factor overexpressed during PCa EMT [36], therefore the reduced membranous Snail observed in extraprostatic extension in our study, and the increased cytoplasmic Snail seen in the Pten−/− mouse model, along with the difference in subcellular localisation of Snail between human, cell line and mouse samples, is difficult to explain, but may represent altered subcellular localisation of a multi-functional protein in these different sample types. The gene discussed is PTEN; the disease is posterior cortical atrophy.