Furthermore, the presence of at least one APOE‐E4 allele was associated with lower values of both Aβ42/40 and Aβ42 and with more severe cognitive impairment in ALS‐nonspecific domains, particularly memory, supporting the role of APOE as major genetic determinant of cognitive impairment through Aβ‐dependent mechanisms. The gene discussed is APOE; the disease is amyotrophic lateral sclerosis.