KRAS and neuroblastoma: KRAS: Kirsten rat sarcoma viral oncogene; NRAS: neuroblastoma-RAS; BRAF: V-Raf murine sarcoma viral oncogene homolog B1; HER2: human epidermal growth factor receptor 2; MSI: microsatellite instability; MSS: microsatellite stable; MMR: mismatch repair