FOXO3 and neuroblastoma: To validate these biochemical screening results in living cells we used SH-EP/FOXO3 neuroblastoma cells stably expressing a 4-hydroxy-tamoxifen (4OHT)-regulated FOXO3(A3)ERtm transgene that undergo apoptotic cell death upon activation of FOXO3 (Obexer et al., 2007; Hagenbuchner et al., 2016b).