Signaling lipids from endogenous, dietary, or microbiota sources constitute an area of considerable excitement, because these signals can induce beneficial effects such as anti-inflammatory protection, enhanced insulin sensitivity, protection against metabolic disease, and increased lifespan in C. elegans (Wang et al., 2008; Kniazeva and Han, 2013; Lim et al., 2013; O'Rourke and Ruvkun, 2013; Folick et al., 2015; Han and Brunet, 2015). Here, INS is linked to metabolic disease.