Jaap Jan Boelens, MD, PhD, Memorial Sloan Kettering Cancer Center, New York, NY, gives an overview of the results of a study exploring the impact of the pulmonary microbiome on patient outcomes after allogeneic hematopoietic stem cell transplantation (alloHSCT). The study identified two inflammatory microbial clusters associated with an increased incidence of alloreactive lung diseases. This data could help intervene earlier in patients at a high risk of developing an alloreactive lung syndrome. This interview took place at the Transplantation & Cellular Therapy (TCT) Meetings of ASTCT™ and CIBMTR® 2022 in Salt Lake City, Utah.