Sperm protein associated with the nucleus on the X chromosome N1 (SPANXN1)

**Sperm protein associated with the nucleus on the X chromosome N1 (SPANXN1)** is a member of the SPANX family of cancer/testis antigens, encoded on the X chromosome as part of the SPANX-N subfamily[1][2][5][6][7]. These proteins are typically localized to post-meiotic sperm cells in the testis, especially in the acrosome, and play roles in spermiogenesis and nuclear organization[7]. SPANX-N proteins share significant sequence identity and are generally small, unfolded proteins[7][5]. While they have canonical testis-specific expression, SPANX-N1 and its close homologs can be found at low levels in some non-testicular tissues and various cancers, including melanoma and other tumors, making them of interest as potential cancer immunotherapy targets[1][2][7]. SPANX family proteins participate in nuclear functions, possibly chromatin regulation, RNA processing, and the organization of protein complexes, especially within the unique environment of sperm nuclei[1][5]. There are currently no known direct drug interactions or mechanisms but, as cancer/testis antigens, they are under investigation as biomarkers and immunotherapeutic targets.

Other names

SPANXN1SPANX-N1SPANX family member N1Cancer/testis antigen family 11, member 6 (CT11.6)Nuclear-associated protein SPAN-Xn1Sperm protein associated with the nucleus on the X chromosome N1