Therefore, the reduced cytokine production in leukopenic C57BL/6CTH−/− compared with leukopenic C57BL/6 upon infection can be attributed specifically to a defect in the antifungal response of lung resident cells, which is in agreement with the increase in the incidence of IPA when the SNP in CTH is present in the recipient compartment. The gene discussed is CTH; the disease is Ito hypomelanosis.