Despite all these treatments, severe asthma can remain uncontrolled, thus requiring adjunctive biological therapies based on the use of monoclonal antibodies directed against immunoglobulins E (IgE), interleukin 5 (IL-5), IL-5 receptor, or interleukin-4 (IL-4) receptor [21,22,23,24,25,26]. This evidence concerns the gene IL4 and asthma.