EPCAM and neoplasm: Intriguingly, loss of CD9 expression correlates with metastasis (Si and Hersey, 1993; Miyake et al, 1996; Zheng et al, 2005) and, as reported at the symposium, a strict co-localisation of CD9 and EpCAM, as seen for membranes of normal colonic epithelium, was no longer found for tumour cell membranes.