JACI: In Practice Deputy Editor, Robert Zeiger, describes the May 2021 issue, the theme of which is “Allergen Immunotherapy.” Theme topics covered include immunological responses and biomarkers, allergens and adjuvants, the role of mobile health technologies, preventative effects, sublingual allergen immunotherapy for asthma, and food oral immunotherapy. Dr. Zeiger then presents the Highlights of the Original Articles in the issue, which are on the topics of COVID-19, Immunotherapy, Allergic Bronchopulmonary Aspergillosis, Anaphylaxis, Asthma, Drug Allergy, Food Allergy, and Immunodeficiency. Read the issue: https://bit.ly/JAIPMay2021. Access JACI: In Practice’s entire library: https://www.jaci-inpractice.org