Rhox homeobox family member 1 pseudogene 3 (RHOXF1P3)

Rhox homeobox family member 1 pseudogene 3 (RHOXF1P3) is a human pseudogene belonging to the Rhox homeobox gene family, typically located on the X chromosome. Unlike classic protein-coding genes, RHOXF1P3 is officially classified as a pseudogene; however, recent studies demonstrate its RNA is highly expressed in certain cancers (especially breast and ovarian), and mass spectrometry data support the existence of peptides derived from its open reading frame in tumors, marking it as a potential source of novel cancer-associated peptide antigens (“dark antigens”) [1][3]. While pseudogenes usually lack protein-coding function, evidence for translation in this case suggests a possibly unique biological or immunological relevance, although its precise cellular role and mechanism remain unclear [1][3]. RHOXF1P3 is not a receptor, enzyme, or classic drug target, nor are there drugs known to act through it, but its upregulation in cancer and potential translation to tumor antigens may make it a subject of future investigation for cancer immunotherapy or as a biomarker [1][3][5]. No common aliases are reported, and no safety concerns or established function in normal physiology are known. The broader Rhox gene family encodes homeobox transcription factors involved in reproductive tissue development and germline maintenance, though RHOXF1P3 itself is considered functionally distinct due to its status as a pseudogene and possible neoantigen source [1][2][4].