Enables DNA binding activity; DNA-binding transcription factor activity; and chromatin binding activity. Involved in several processes, including cellular response to epidermal growth factor stimulus; luteinization; and receptor signaling pathway via JAK-STAT. Located in cytosol and nucleus. Human ortholog(s) of this gene implicated in growth hormone insensitivity syndrome with immune dysregulation 1 and growth hormone insensitivity syndrome with immune dysregulation 2. Orthologous to human STAT5B (signal transducer and activator of transcription 5B). [provided by Alliance of Genome Resources, Apr 2022]