Currently, there are inadequate therapeutic options for major respiratory diseases caused by prolonged inflammation leading to tissue damage and infection. Regenerative medicine for lung diseases has largely focused on the lung tissue lining, but the lung immune system has often been overlooked in approaches to disease treatment. The most abundant cell population in the lung airways are the alveolar macrophages (AM), which are part of the innate immune system and play a critical role in inflammation clearance. Dr. Martin Post, a Senior Scientist in the Translational Medicine program at SickKids leads his research group with the focus on lung-related development. The Post team has generated human alveolar-like macrophages (hALMs) from stem cells as a cell therapy for lung diseases including respiratory syncytial virus (RSV) and bacterial infections due to cystic fibrosis, which may mitigate disease severity and progression. hALM introduction in rodent studies showed lung specificity and did not elicit an immune response. These engineered hALMs also have the ability to express various factors including IL-10 and provide a non-immunogenic method to replenish alveolar macrophage populations in individuals with compromised lung immune systems.