Transcriptional activator that functions upstream of the let-60/Ras and let-23/EGFR signaling pathways to positively regulate lin-3 expression and thereby promote vulval induction (PubMed:20230814). Plays a role in excretory duct development (PubMed:20230814). Plays a role in male tail development (PubMed:20230814). Expressed in the somatic gonad, neurons, hypodermal cells, seam cells, the excretory system, and intestinal cells (at protein level). Expressed in most cells of the embryo beginning from the 100-cell stage (at protein level) (PubMed:20230814). Expressed throughout larval development in the excretory system, anterior neurons and the hypodermis (at protein level) (PubMed:20230814). Expressed in vulval precursor cells and their descendants during the mid-larval stages and is highly expressed in the somatic gonad from the L3 larval stage to adulthood (at protein level) (PubMed:20230814). RNAi-mediated knockdown results in embryonic or larval lethality (PubMed:20230814). Surviving animals exhibit slow growth, gonad migration defects, vulval induction defects and reduced lin-3 expression (PubMed:20230814). Larvae that develop into adults are sterile, and only few produce embryos (PubMed:20230814). RNAi-mediated knockdown in males results in tail defects including underdeveloped tails, spicule defects and missing rays (PubMed:20230814). RNAi-mediated knockdown in a lin-3 e1417 mutant background abolishes vulval induction (PubMed:20230814). RNAi-mediated knockdown in a let-23 sa62 gain of function mutant background partially suppresses the multivulva phenotype in the let-23 mutant (PubMed:20230814). RNAi-mediated knockdown in a let-60 n1046 gain of function mutant background suppresses the multivulva phenotype in the let-60 mutant (PubMed:20230814). Belongs to the SBNO family.