In vitro treatment with 5-Aza-2’-deoxycytidine, a demethylating agent, successfully restored caspase 8 expression and sensitivity to TRAIL-induced apoptosis in cell line models of PNET [37], neuroblastoma [38, 40, 42] and medulloblastoma [42]. This evidence concerns the gene CASP8 and primitive neuroectodermal tumor.