DEAD box 1 (DDX1) was first identified by differential screening of a retinoblastoma cDNAlibrary, and subsequently found to be amplified and overexpressed in a subset ofretinoblastoma and neuroblastoma tumours and cell lines8, 9, 10, 11, 12.DDX1 expression is ubiquitous, with proliferating cells and cells derived fromneuroectodermal tissues expressing the highest levels of DDX18, 13. This evidence concerns the gene DDX1 and neoplasm.