The marked differences in susceptibility to IPA infection among hematological patients (with or without allo-HSCT) suggest that the effective immune response against Aspergillus is determined by both environmental and host genetic factors [44, 45] . Studies on genetic polymorphisms in genes coding for components of the innate immunity have supported this hypothesis [19, [23] [24] [25] [26] [27] [28] [29] [30] 46] .