IL10 and combined immunodeficiency: Although this cytokine is considered an unparalleled candidate for targeted immunomodulation in CID (21, 22, 79), its context-dependent and paradoxical immunostimulatory effects, as well as the pharmacological problems associated with systemic rIL-10 administration appear to be accounted for the poor safety/efficacy outcomes observed in clinical trials (18, 21, 22), further indicating that novel strategies are required to harness IL-10 therapeutic potential.