Anti-ESX antibodies are used in antigen-specific immunodetection in biological samples. The target ESX is a known alias name of the protein E74 like ETS transcription factor 3, encoded by the ELF3 gene in humans. This 371-amino acid residue protein is reported to be a transcriptional activator that binds and transactivates ETS sequences containing the consensus nucleotide core sequence GGA[AT]. It is localized to the nucleus and cytoplasm of the cell. It is reported to be expressed in many tissues, such as the bronchus and endometrium. These ESX antibodies are widely used in Western Blot experiments, among other applications.