C9 and amyotrophic lateral sclerosis: The ABC included 107 ALS patients (45 ALS‐F, 36 ALS‐S, and 26 C9+ve ALS; mean age at baseline: 61.9 (SD ± 10.7)) while the PGB cohort included 129 ALS patients (55 ALS‐F, 54 ALS‐S, and 20 C9+ve ALS; mean age at baseline: 58.6 (SD ± 11.57)).