As IFN-beta was found to be upregulated in the NPF of asthmatic children with Gram-negative colonization as compared to those children with asthma and a Gram−/+ bacteria colonization and has recently been shown to directly blunt IL-33 induced proliferation of bone marrow-derived ILC2 cells13, we next analyzed the expression of IL-33 receptor (R) (ST2: suppressor of tumorigenicity 2), signature of ILC2 cells and Th2 cells, in the peripheral blood of the cohorts of pre-school children taking into consideration their bacterial colonization in the NPF. Here, IL1RL1 is linked to asthma.