Conversely, SOD2 levels are elevated in malignant versus benign tumours; SOD2 up-regulates MMP-dependent tumour invasion and metastatic dissemination [28], [40]–[42]; SOD2 increases tumour cell resistance to ionising radiation and chemotherapy-induced toxicity [17], [18], [22], [24], [26]–[28], [31], [33], [39], [43], [44]; and higher levels of SOD2 combined with lower levels of ROS characterise normal stem and cancer stem cells and promote chemotherapeutic and radio-therapeutic resistance within the cancer stem cell niche [29], [45], [46]. Here, SOD2 is linked to cancer.