CFTR and allergic bronchopulmonary aspergillosis: For example, mutations in the CFTR gene may lead to ABPA, and mances-binding lectin gene mutations may result in chronic necrotizing aspergillosis or IPA.[19] Immunosuppression is a major risk factor for the development of IPA.[20] Although the patient in this case did not use corticosteroids or itraconazole, it is still possible that other factors, such as an increased fungal load, could have led to the development of IPA.