What is the function of prostate-specific antigen in normal males?

A functional protein: It is a glycoprotein made by the cells of the prostate. Psa liquefies/thins out the semen in the seminal glands and allows sperm to swim freely. It is also believed to be instrumental in dissolving the cervical mucus, allowing the entry of sperm into the uterus and up etc....Beyond that, I have no idea what else it does. It is used as tumor marker for prostate cancer monitoring etc..Good luck.