End-stage plasma ferritin. At end-stage, plasma ferritin in SOD1G93A mice (ferritin 57.1 ± 4.9 ng/ml) was increased compared with WT (ferritin 24.0 ± 4.4 ng/ml, P < 0.001), H67D (ferritin 19.9 ± 5.3 ng/ml, P < 0.001), and double transgenic mice [ferritin 37.5 ± 4.9 ng/ml, P = 0.035 (n = 13–19 per group), F(3, 54) = 11.38, P < 0.001].