Multivariable regression indicated poorer prognosis (p < 0.05) according to higher plasma NfL levels (HR [95% CIs] = 1.01 [1.01–1.01]), older age at evaluation (1.11 [1.04–1.19]), higher Goldman score (0.87 [0.76–0.99]), and FTD‐ALS or PSP/CBS phenotypes (2.72 [1.64–4.49]; see Table 2). The gene discussed is NEFL; the disease is amyotrophic lateral sclerosis.