IL4 and allergic bronchopulmonary aspergillosis: In our studies, the presence of the val75 allele, located within the IL-4 binding region, was found in 87.5% of ABPA subjects examined, while the cytoplasmic SNPs were present much less frequently at 27.3% for ala400, 27.3% pro503, 27.3% arg576, and 9.1% arg431.