SLC11A2 and amyotrophic lateral sclerosis: We used free text and the medical subject heading (MeSH) terms “amyotrophic lateral sclerosis,” “ALS,” “iron,” “iron metabolism,” “iron accumulation,” “biomarker,” and “iron chelation.” Then, we searched for each marker of iron metabolism (DMT1, TfR1, ferritin, ferroportin, hepcidin, HFE,...) AND ALS (OR “amyotrophic lateral sclerosis”).