Furthermore, missense mutations in the key genes IL-13, IL-13Rα1, IL-13Rα2, IL-4, IL-4Rα are common, while no case reports have been published on any immune deficiency or increased risk of neoplastic disease associated with such mutations, suggesting that these genes do not harbor non-redundant roles in adult outbred humans. This evidence concerns the gene IL4R and neoplasm.