The IL33/IL13 circuit induces expansion of the DCS cell population. (A) The IL33/IL13 axis was driven by 4 daily injections of 0.4 ug IL33. In situ hybridization for the DCS cell marker Reg4 was performed on distal colons showing increased numbers of Reg4+ cells in IL33-injected mice. n = 5 mice per group. Scale bar: 50 μm. (B) To test the requirement for IL13 in vivo, expression of DCS cell markers Reg4, Spink4, Kit, and Retnlb expression levels were quantified by quantitative polymerase chain reaction in colonic tissue of wild-type or IL13-/- mice injected with IL33. N = 7–9 mice per condition. Data were analyzed by 2-way analysis of variance with the Tukey post hoc test or 2-tailed Student t test. ∗P < .05, ∗∗∗∗P < .0001. ISH, in situ hybridization; PBS, phosphate-buffered saline; WT, wild-type.