NEFL and amyotrophic lateral sclerosis: This meta‐analysis also reports lower effect sizes for blood NfL (1.59; 95% CI 1.25–1.92) levels in ALS (n = 1074) compared to healthy controls (n = 707) (Sferruzza et al., 2021) with respect to the earlier performed meta‐analysis on a larger dataset with an about six times larger effect size of 9.64 (Forgrave et al., 2019).