SELENOV (selenoprotein V) is a member of the thioredoxin-like selenoprotein family that functions as a regulator of energy metabolism and redox homeostasis 1. SELENOV contains a characteristic CxxU motif and eGxFEI sequence shared with other thioredoxin-like selenoproteins 2. The protein exhibits tissue-specific expression, being expressed essentially only in the testes with unknown cellular localization 2. Functionally, SELENOV acts as an inhibitor of body fat accumulation and activator of energy expenditure through a novel protein-protein interaction with O-GlcNAc transferase (OGT) 1. Knockout studies demonstrate that loss of SELENOV leads to increased body weight, enhanced fat mass accumulation, and decreased energy expenditure through dysregulation of lipogenesis and lipolysis pathways 1. SELENOV also affects selenium metabolism regulation, as its knockout alters selenoprotein expression patterns and tissue selenium concentrations in response to dietary selenium and fat intake 3. In disease contexts, SELENOV is significantly downregulated in thyroid cancers and associated with poor prognosis, potentially through regulation of redox processes and ER calcium homeostasis 4. The protein is also incorporated into prognostic signatures for breast cancer outcomes 5.