Transcription factor (By similarity). Plays a role in embryogenesis and later development, perhaps acting redundantly with forkhead protein fkh-2 (PubMed:11044397). Expressed in the AB lineage at the 185 cell stage (PubMed:11044397). Also expressed in the lineage of the D founder cell in the 185 cell embryo, continuing to at least the comma stage (PubMed:11044397). Expressed in Z1 and Z4 cells at the comma stage (PubMed:11044397). RNAi-mediated knockdown in adults has little or no phenotypic effect on adult or their progeny (PubMed:11044397). However, simultaneous knockdown of forkhead gene fkh-2 in adults causes 8% embryonic lethality, and nearly 80% arrest after hatching as L1 stage larvae (PubMed:11044397).