Probably a receptor-regulated SMAD (R-SMAD) that is an intracellular signal transducer and transcriptional modulator activated by TGF-beta-like daf-7 signaling. Plays a role in TGF-beta-like daf-7 signaling in regulating entry into a developmentally arrested larval state known as dauer, in response to harsh environmental conditions; partially redundant with R-SMAD daf-14. Plays a role in inhibiting mitosis and promoting a switch to meiosis in the germ line, perhaps by down-regulating lag-2 transcription in the gonadal distal tip cells (DTCs). In cooperation with orphan nuclear receptor nhr-69 modulates the Insulin/IGF-1-like signaling (IIS) pathway, perhaps by regulating expression of the potassium channel exp-2, which in turn modulates the secretion of the insulin-like peptide daf-28