Alveolar macrophages and epithelial cells: The art of living together.

In this issue of JEM, Gschwend et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20210745) reveal the indispensable role of alveolar epithelial cells type 2 in controlling the density of alveolar macrophages. This study highlights the intricate crosstalk that lung stroma and macrophages undergo to maintain homeostasis.