Participates in the inductive signaling pathway downstream of let-60 Ras and the RAF/MAP kinase cascade to regulate specification and differentiation of many cell types (PubMed:11063686). Positively regulates the fate of vulval precursor cells (PubMed:3996896, PubMed:7867931, PubMed:9806929). Required for induction of the P12 and excretory duct cell fates. In males, it is also required for proper formation of spicules. Does not function in the signaling pathway that promotes exit from pachytene (PubMed:11063686). Plays a role in responses to M.nematophilum-mediated bacterial infection by promoting tail swelling and preventing constipation (PubMed:15268855). Expressed in seam cells and all six vulva precursor cells (VPC). After VPC division, expression is restricted to descendants of the VPC cell lineages P5.p, P6.p and P7.p (at protein level). Expressed in all stages but highest during L1, L2 and L3 stages (at protein level).