Asthma is a common chronic respiratory disease that causes substantial morbidity and has been challenging to treat due to its heterogeneous onset, environmental triggers, severity, and treatment response. To update the field on the rapid advances in this field, Precision Approaches to Heterogeneity in Asthma follows its highly successful predecessor, Heterogeneity in Asthma. In this new volume, noted authorities Allan R Brasier and Nizar N Jarjour and a cadre of leaders in the field incorporate new work advancing our understanding of phenotypes (endotypes) of disease, regional variations in ventilation, systems approach to analyzing the findings from studies of inducible phenotypes, and emerging results of biomarker-informed clinical trials. This work will facilitate our current understanding of the spectrum of disease etiology, prognosis, and the likelihood of responding to the range of available therapeutic interventions.