Our research addresses developmental, cellular, molecular, and functional aspects of epithelial biology. In particular, we have focused on understanding how the dimensions and shapes of epithelial tubes are controlled. The correct size and shape of tubular epithelia is critical for the function of vital organs, such as our lungs, kidneys, and blood vessels. While tubule size is precisely controlled during normal organ development, one hallmark of diseases, such as Polycystic Kidney Disease, is the loss of the capacity of epithelial cells to regulate tubular dimensions. Despite this medical significance, it is not understood how epithelial cells measure, adjust, and maintain defined tubular dimensions. To address these basic questions, we use primarily the Drosophila tracheal (respiratory) system, a network of gas-filled tubes, as an accessible and comparatively simple model. We apply a combination of molecular, genetic, cell biological, and quantitative imaging approaches to analyze cellular behavior during tube morphogenesis at the single-cell level.