Anti-tetra-peptide repeat homeobox 1 antibodies are used in antigen-specific immunodetection in biological samples. The target tetra-peptide repeat homeobox 1 is a known alias name of the protein tetrapeptide repeat homeobox 1, encoded by the TPRX1 gene in humans. This 411-amino acid residue protein is reported to be a transcription factor expressed after fertilization required for zygotic genome activation (ZGA), a critical event in early embryonic development during which the developmental control passes from maternally provided mRNAs to the expression of the zygotic genome after fertilization. It is localized to the nucleus of the cell.