Since recruitment and activation of polymorphonuclear neutrophils and mononuclear cells into the lungs is a crucial event in the early phases of IPA [48], we could attribute an increased susceptibility of Trem1−/- mice to an impaired pulmonary inflammation in response to A. fumigatus that impacted survival in the immunosuppressed host. Here, TREM1 is linked to Ito hypomelanosis.