RB1 and retinoblastoma: The identified methylation groups were PB-miRNA-1 (n = 10), PB-RB1 (n = 1), retinoblastoma-MYCN activated (n = 1), PPTID KBTBD4-altered (n = 1), papillary tumor of the pineal region (n = 1), medulloblastoma (MB) WNT activated (n = 1), MB non-WNT/SHH (n = 1), CNS embryonal tumor with BRD4-LEUTX fusion (n = 1) and unclassified N/A (n = 3).