TARDBP and amyotrophic lateral sclerosis: Frozen brain samples (Supplementary Table 2) (9 ALS; 9 normal controls) were analyzed by mass spectrometry after immunoprecipitation with a TDP-43 antibody (Supplementary Table 4) to identify deamidated asparagine residues in TDP-43, which were detected in 89% of ALS brains and in 55% of the controls.