TSLP (thymic stromal lymphopoietin) is an epithelial-derived cytokine that functions as a central regulator of immune responses to environmental insults including allergens, viruses, and pollutants 1. TSLP operates through the JAK-STAT signaling pathway by binding to TSLP receptor (TSLPR), which allosterically activates TSLP to recruit the interleukin-7 receptor α-chain (IL-7Rα) 2. This interaction triggers cascades of pro-inflammatory responses, including activation of dendritic cells that promote type 2 helper T cell (Th2) differentiation and production of IL-5, IL-13, and IL-10 13. TSLP plays a major pathogenic role in allergic asthma and atopic dermatitis, driving both type 2-driven eosinophilic inflammation and non-type 2 responses 1. Clinical evidence demonstrates that anti-TSLP monoclonal antibody tezepelumab reduces allergen-induced bronchoconstriction, eosinophil levels, and asthma exacerbations across inflammatory endotypes 45. Tezepelumab is now approved for poorly controlled moderate-to-severe asthma regardless of phenotype 5. Emerging evidence suggests TSLP involvement in chr5 rhinosinusitis with nasal polyps, with preliminary data showing tezepelumab efficacy in patients with comorbid asthma 6. Novel therapeutic approaches include bispecific nanobodies co-targeting TSLP and IL-13 7 and small-molecule TSLP receptor inhibitors 8.