C9orf72 and amyotrophic lateral sclerosis: Current rodent ALS models include the Friend leukemia virus B (FVB)-C9orf72 bacterial artificial chromosome (BAC) mouse that carries C9orf72 mutations most associated with ALS, Cu/Zn SOD1-G93A mice that encode the human SOD1 protein containing the G93A mutation, and the TDP43-Q331K mouse model that mildly overexpresses human mutant TDP-43 [243].