CASP8 and neuroblastoma: Several tumor suppressor genes such as caspase 8 (CASP8), Ras association (RalGDS/AF-6) domain family member 1 (RASSF1A), cycling D2 (CCND2), CD44, O-6-methylguanine-DNA methyltransferase (MGMT), and PYD and CARD domain containing (TMS1), have been shown to be silenced in NB by aberrant hypermethylation of their promoters [16-18].