Use of the C. elegans model has also delineated several conserved host pathways modulating infection outcomes, including the p38 mitogen-activated protein kinase (MAPK), TGF-β and DAF-2 insulin/IGF-1 signalling pathways (Kim et al., 2002; Mallo et al., 2002; Garsin et al., 2003). Here, IGF1 is linked to infection.