In 2022, an anti-thymic stromal lymphopoietin (TSLP) antibody was approved for use in Europe for the treatment of severe asthma in patients with no phenotype or biomarker limitations [2] This agent, tezepelumab, has shown some effectiveness in individuals with type 2-low asthma, however, the observed effects are less convincing compared to the effectiveness in type 2-high patients. This evidence concerns the gene TSLP and asthma.