The effect of removing cysteines 6 and 111 on the yield of amyloid, even in the absence of ALS mutations, is difficult to explain; the replacement of these two cysteines may either cause some destabilization of the tertiary structure of SOD1 [42] or promote the formation of amyloid instead of other types of aggregates, like amorphous aggregates. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.