MATR3 and amyotrophic lateral sclerosis: To circumvent the confounding effects of overexpression of exogenous MATR3 and to investigate the impact of an ALS-linked mutation at the physiological level in mice, we introduced a single amino acid change, S85C, in the endogenous Matr3 allele using the CRISPR/Cas9 system, hereby establishing MATR3 S85C knock-in mice.