Signal Transducer and Activator of Transcription

**Semantic type:** Amino Acid, Peptide, or Protein

**Definition:** A family of cytoplasmic proteins that are activated by phosphorylation in response to a large number of cytokines, growth factors, and hormones. They dimerize and translocate to the nucleus upon activation, where they bind to regulatory cis-elements of specific target genes.

**Synonyms:** - STAT - STAT Protein