Also, the observation that morphine can induce Beclin 1 and Atg5-dependent autophagy in human neuroblastoma SH-SY5Y cells and in the rat hippocampus [56] together with the recent report that autophagy in the spinal dorsal horn might play a role in morphine tolerance [57] seem to support an involvement of this process in the mechanisms of central sensitization occurring at the spinal cord. This evidence concerns the gene ATG5 and neuroblastoma.