Several biomarkers have also been associated with ALS prognosis such as UNC13A gene polymorphism, blood ferritin levels, blood creatinine levels, serum neurofilament light chain, or 25OH vitamin D (25OH VD) levels; but to date, none of them has been unequivocally linked to ALS onset or progression (2, 4, 7). This evidence concerns the gene NEFL and amyotrophic lateral sclerosis.