Meeting summary: European Workshop on Stem Cells, European Centre for the Validation of Biomedical Testing Methods, Institute for Health and Consumer Protection, Joint Research Cen... by Gribaldo, L, Alison, M, Andrews, P, Bremer, S, Donovan, P, Knaän-Shanzer, S, Mertelsmann, R, Spielmann, H, Testa, N, Triffitt, J, Zipori, D, de Wynter, E