However, most KI strains express the mouse protein of interest, thus not modeling human biochemistry that can be important for proteinopathies; for example, human SOD1 protein has distinct biochemical properties associated with specific residues that are not present in the mouse, but are important for SOD1 misfolding, aggregation, and inferring neuronal toxicity in the context of ALS (Crown et al., 2020; DuVal et al., 2019; Nagano et al., 2015; Perri et al., 2020). This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.