“…The cytokines IL-4, IL-5 and IL-13, the epithelial growth factor amphiregulin, and eosinophil and AAM infiltration are all necessary for normal ductal outgrowth (Aupperlee et al, 2014; Colbert et al, 2005; Khaled et al, 2007); all of these findings are consistent with a role for ILC2s, which promote adipose tissue eosinophils and AAM (Molofsky et al, 2013b), produce a majority of tissue IL-5 and IL-13 (Nussbaum et al, 2013), and are a source of amphiregulin (Monticelli et al, 2011). Definitive studies, including the potential role of mammary gland IL-33, ILC2s, and Tregs, are needed.…”