The glycerol backbone of phospholipids derives from noncarbohydrate precursors in starved lung cancer cells gan Leithner, K, Triebl, A, Trötzmüller, M, Hinteregger, B, Leko, P, Wieser, B, Grasmann, G, Bertsch, A, Züllig, T, Stacher, E, Valli, A, Prassl, R, Olschewski, A, Harris, A, Köfeler, H, Olschewski, H, Hrzenjak, A