RELMβ promotes secretion of Muc2 (Krimi et al., 2008), regulates macrophage and CD4+ T cell responses in response to helminth infection (Nair et al., 2008), and promotes CD4+ T cell recruitment and mediation of IEC hyperplasia during pathogenic intestinal bacterial infection (Bergstrom et al., 2015). Here, CD4 is linked to helminthiasis.