Sperm protein 17: clinical relevance of a cancer/testis antigen, from contraception to cancer immunotherapy, and beyond.

Sperm protein 17 belongs to the cancer/testis antigen family and was found to play a key role in the cell fusion process between the mammalian spermatozoa and egg. Sperm protein 17-specific autoantibodies in vasectomized males suggest its high expression in the testis. Sperm protein 17 expression levels are low or absent in normal tissues, other than the testis. Sperm protein 17 is expressed by tumors, including ovarian cancer, indicating that it is an ideal target for cancer immunotherapy, and plays a role in tumorigenesis and drug resistance. This review recapitulates the milestones of sperm protein 17 research and highlights its potential use in translational medicine.