HEPH and amyotrophic lateral sclerosis: In contrast, although total spinal cord copper levels are reportedly unchanged or elevated in SOD1G37R mice,7–9,54 these mice exhibit a functional deficit in the activity of cuproenzymes, including SOD1, ceruloplasmin, and hephaestin.7–9 These changes are also apparent in the spinal cords of human ALS cases.10 Thus, there appears to be a disconnect between copper levels and copper-dependent processes in ALS.