Forkhead box protein O (FOXO) transcription factor DAF-16 (DAF-16)

Forkhead box protein O (FOXO) transcription factor DAF-16 is the single FOXO transcription factor ortholog in *Caenorhabditis elegans*, critically regulating gene expression programs that control lifespan, metabolism, development (including dauer diapause), fat storage, and stress resistance[1][2][4][7]. It is the principal downstream effector of the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway (IIS), and is activated when IIS is reduced, leading to nuclear localization and upregulation of stress resistance and longevity-associated genes[4][7]. DAF-16/FOXO not only responds to IIS but also to other signals, such as oxidative stress, innate immunity signals, and cellular damage[2][6]. It operates via distinct isoforms (e.g., DAF-16a, DAF-16d/f), whose tissue-specific and temporal patterns contribute to organismal lifespan and metabolic responses[1]. While DAF-16/FOXO is a critical research focus and a key regulator of pathophysiology in *C. elegans*, it is not considered a direct therapeutic target or druggable protein in the conventional pharmacological sense. Its role is instead central to understanding conserved mechanisms of aging and cellular stress resistance in metazoans[2][4][5][7]. The DAF-16 transcription factor is a central nodal point in aging, metabolic, and stress-resistance regulatory networks in *C. elegans*, acting as the major effector of insulin/IGF-like signaling and multiple stress pathways. It is not a canonical drug target or therapeutic molecule, but rather a highly studied transcription factor fundamental to longevity and stress resistance research[1][2][4][7].

Other names

FOXO transcription factor DAF-16FOXOCe-FOXOC. elegans FOXO