*2.4. Cell Lines*

NLF and BR6 neuroblastoma cells were kindly provided by Dr. Garrett Brodeur (Children's Hospital of Philadelphia, Philadelphia, PA, USA). These cell lines are routinely tested for integrity and authenticity, for endotoxins, mycoplasma, bacterial, and other viral contaminations, as well as genetic authenticity by multiplex PCR techniques. WS1 fibroblasts were used as a model for non-tumor cells. For the present study, the cells were grown in DMEM supplied with 10% HS, Penicillin, and Streptomycin at 37 ◦C in a 5% CO<sup>2</sup> humidified atmosphere. They were maintained in 25 cm<sup>2</sup> culture flasks (Corning, Tewksbury, MA, USA) and harvested using 0.25% Trypsin in 0.2 g/L EDTA solution.
