While cytoplasmic aggregates of an ALS-linked FUS mutant were reported to inhibit U12-mediated splicing of a subset of introns by trapping of snRNAs in aggregates (Reber et al., 2016), and ALS-linked mutant-dependent splicing changes have previously been reported in patient fibroblasts (Sun et al., 2015) as well as in motor neuron precursor cells derived from iPSCs (Ichiyanagi et al., 2016), no significant splicing changes in the nervous system of humanized mutant FUS mice were identified despite initiation of adult-onset disease. This evidence concerns the gene FUS and amyotrophic lateral sclerosis.