IFNAR1 and Down syndrome: Nevertheless, in patients with Down syndrome, several risk factors for developing severe infections have been described, such as dysregulation of the immune system due to the overexpression of genes encoded on chromosome 21 with immune regulation functions by the interferon receptors IFNAR1 and IFNAR2, and IFNGR2 and IL10RB that serve as ligands for cytokines interleukin (IL)-10, IL-22, and IL-26.