PTPRC and allergic rhinitis: Neutrophils that express Sialic acid-binding, Ig-like lectin (Siglec)-F, have been found in the nasal mucosae of mice in a model of allergic rhinitis.35 Siglec-F+ neutrophils have an activated phenotype, produce reactive oxygen species (ROS) and have higher phagocytic activity than Siglec-F− neutrophils.35,36 In order to quantify tissue-resident cells, we used a validated intravenous labeling approach,37 where mice are injected i.v. with fluorochrome-labeled anti-CD45 antibody 10 min before euthanasia and immune cells were prepared from nasal tissue and lung.