SOD2 and neoplasm: In conclusion, our study shows that TrkAIII promotes SH-SY5Y NB cell resistance to agents that induce mitochondrial free radical ROS-mediated death by up-regulating SOD2 expression, increasing mitochondrial SOD2 activity and attenuating the accumulation of mitochondrial free radical ROS, in association with up-regulated mitochondrial capacity to produce H202 and within the context of a more tumour stem cell-like phenotype.