Toshitaka Seki -
Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo
Kazutoshi Hida -
Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo
Mitsuhiro Tada -
Division of Cancer-Genes, Institute for Genetic Medicine, Hokkaido University, Sapporo
Izumi Koyanagi -
Hokkaido Neurosurgical Memorial Hospital, Sapporo, Japan
Yoshinobu Iwasaki -
Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo