CASP9 and neoplasm: Based on the hypothesis that neuroblastomas are tumours in which mutated cells have abnormalities in their programmed cell death and the fact that CASP9 and DFFA are localized in the neuroblastoma tumour-suppressor hot-spot region (1p36.2-3), the purpose of the present study was to investigate whether mutated CASP9 or DFFA could be causative in the development of neuroblastoma tumours in childhood.