In fact, research continues to characterize novel pleiotropic biological roles for Lf; Lf was observed in the human brain by immunohistochemistry and was associated with aging, particularly with multiple central nervous system (CNS) diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Down’s syndrome, Pick’s disease, sporadic amyotrophic lateral sclerosis, amyotrophic lateral sclerosis, cerebrovascular disease, developmental delay in children and other neurological diseases [35,40,41,42,43,44,45,46,47,48]. The gene discussed is LTF; the disease is Down syndrome.