FOXO1 and primitive neuroectodermal tumor: Although there have been no published studies specifically addressing FOXO1A expression levels in CNS-PNETs, the vast majority of primary CNS-PNET specimens assayed using the superseded HG-UL95A GeneChip were called "absent" for FOXO1A expression in the largest published microarray study of 68 CNS-PNET specimens [17], suggesting that FOXO1A expression is generally low in primary CNS-PNETs.