We are developing gene therapy for the lung, which could treat diseases ranging from lung cancer to asthma. The major limiting factor for lung gene therapy has been the ability to deliver a gene into cells without causing toxicity. Here, we used lipid nanoparticles (LNPs) invented in our lab to deliver a gene that causes cells to turn red, to test how effective our LNPs were. We found very good delivery to a wide variety of lung cells, including important lung cell types such as club cells (green) and ciliated cells (purple border).