ILC2, but not CD4+ T cells, in the mesenteric lymph nodes express IL-25R. CD4+ T cells (CD45+, CD3+, CD4+) (left) and ILC2 (CD45+, CD19-, CD5-, CD11b-, CD11c-, NK1-1-, CD4-, CD90-2+, CD25+, CD127+, IL-33R+) (right) were stained with 0.125 µg of Rat IgG2a K Isotype Control PE (Product # 12-4321-80) (blue histogram) or 0.125 µg of Anti-Mouse IL-25R (IL-17RB) PE (purple histogram). Single, viable cells were used for analysis. Data are courtesy of the Artis laboratory (Department of Microbiology and Institute for Immunology, Perelman School of Medicine, University of Pennsylvania).