SOD1 and cancer: The hazard ratios of lowest blood levels of SOD activity and Zn/Cu ratios to mortality rates from cancer were 1.36 (95% C.I., 0.59-3.10) and 1.97 (95% C.I., 0.84-4.63), and those to mortality rates from all causes were 1.31 (95%C.I: 0.76-2.27) and 1.99 (95%C.I.: 1.14-3.46), respectively, in comparison with subjects with highest values for these factors.