MUC5AC and asthma: IL-13 stimulation recapitulates many of the morphologic features of the diseased epithelium in severe asthma, including increased cell size, epithelial cell hyperplasia, MUC5AC staining, and formation of eGC (11, 30–35) (Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.187904DS1).