Reactome: a knowledge base of biological pathways - Joshi-Tope, G; Gillespie, M; Vastrik, I; D'Eustachio, P; Schmidt, E; de Bono, D; Jassal, B; Gopinath, GR; Wu, GR; Matthews, L; Lewis, S; Birney, E; Stein, L (Nucl Acid Res, 2005)
Database issue