Further Evidence for a Somatic KRAS Mutation in a Pilocytic Astrocytoma - Janzarik, W G; Kratz, C P; Loges, N T; Olbrich, H; Klein, C; Schäfer, T; Scheurlen, W; Roggendorf, W; Weiller, C; Niemeyer, C; Korinthenberg, R; Pfister, S; Omran, H (Neuropediatrics, 2007)