The first association of the NBAS gene with immunodeficiency was established by Garcia Segarra et al. in two patients who had NBAS mutations and suffered from recurrent viral and bacterial infections, including pneumonia and middle ear infections, and who were reported to have hypogammaglobulinemia, reduced NK cells, and abnormal antibody production in response to vaccinations. The gene discussed is NBAS; the disease is susceptibility to pneumonia measurement.