Other potential environmental triggers like vitamin D deficiency [46–48], a hypothetical loss of intestinal helminths after his transfer from Ghana to Italy [31], a hypothetical decreased induction of oral immune tolerance due to a reduced amount oral antigens [49], a possible induction of IL-17 due to changes of the intestinal flora [50–52], might have promoted a proinflammatory immune response polarization, thus contributing to ALS development in the described patient. The gene discussed is IL17A; the disease is vitamin D deficiency.