RELN and early-onset autosomal dominant Alzheimer disease: Physiological Reelin is abundant in the bloodstream, being fundamental for brain, heart, liver, gut, and eye homeostasis, but it might also work as a pro-inflammatory and pro-thrombotic factor, playing critical roles in inflammatory and autoimmune diseases (multiple sclerosis, Alzheimer’s disease, arthritis, atherosclerosis) and the regulation/dysregulation of cancer cells [21,33].