MYCN and neuroblastoma: Children’s Oncology Group (COG) has established the risk stratification system relying on five characteristics: International Neuroblastoma Staging System (INSS) stage, patient age at diagnosis, MYCN gene status, DNA index, and International Neuroblastoma Pathology Classification (INPC) (London et al., 2005; Shimada et al., 1999; Peuchmaur et al., 2003).