TSLP and TSLPR protein expression analysis: Human TSLP and TSLPR protein was exclusively detected in humanized B-hTSLP/hTSLPR mice compared to wild-type mice by ELISA and flow cytometry, respectively. Analysis of leukocyte and T cell subpopulations in B-hTSLP/hTSLPR mice: Introduction of human TSLP and TSLPR in place of its mouse counterpart does not change the overall development, differentiation or distribution of these splenic immune cell types. Functional analysis using a B-hTSLP/hTSLPR-asthma model: Tezepelumab treatment reduced OVA-specific IgE and IL-5 levels and eosinophilic infiltration in B-hTSLP/hTSLPR-asthma mice.