Research Training in Pulmonary Immunology and Allergy at MGH is a T32 renewal application that brings together research programs of the Massachusetts General Hospital (MGH) Division of Pulmonary and Critical Care Medicine (DPCCM), Allergy and Clinical Immunology Unit (ACIU), and Center for Immunology and Inflammatory Diseases. This Training Program was created principally to provide comprehensive training for physician-scientists in the DPCCM and ACIU fellowship programs interested in lung immunology and allergic inflammation. The Program is designed to prepare the next generations of physician-scientists and PhD- scientists to be leaders in lung immunology and allergy related research. In the first 9 years, this Program has been highly successful with no unfilled slots and 100% rate of retention in academic centers or in industry research. In addition, all but one former trainee who finished their T32 support more than 3 years ago have published first author papers and submitted grant applications, and 50 research grants have been awarded. In this renewal application we capitalize on this success and momentum and provide training in 12 scientific disciplines: (i) Adaptive Lung Immunity; (ii) Innate Lung Immunity; (iii) Allergic Sensitization, Tolerance & Immunodeficiency; (iv) Lung Injury, Repair & Regeneration; (v) Molecular Epidemiology & Genetics of Lung Disease and Allergy; (vi) Health Care Delivery Science in Pulmonary and Allergy; (vii) Translational & Precision Medicine; (viii) Systems Biology, Single Cell Genomics & Epigenetics; (ix) Microbiome; (x) Novel Imaging Modalities; (xi) Metabolism; (xii) and Nanotechnology and Organoids. The Program will have basic, translational, health outcomes and epidemiology components. Specifically, we seek to provide: 1) opportunities for mentored research in disciplines that have the potential for high-impact discoveries; 2) outstanding research training through didactics, seminars, and comprehensive mentoring; and 3) an environment and infrastructure that fosters scholarly activity and career development into independent scientists. This application requests a continuation of 8 training positions that will be allocated to trainees who are committed to 2 to 3 years of research training. MD or MD/PhD candidates will be drawn from the DPCCM and ACIU fellowship programs. PhD trainees will be chosen from postdoctoral fellows in the mentor laboratories who have demonstrated a commitment to careers in pulmonary or allergy research. The 33 mentors (12 women, 4 underrepresented minorities in medicine) in this Program were carefully chosen based on their track record of publications, grants, mentoring, collaboration and interest in lung immunology and allergy. MGH provides an outstanding scientific and training environment for its over 2,000 investigators and thousands of trainees with numerous training grants, research centers, trainee support groups and over $1.2 billion in research grant awards. Furthermore, ...