But some tests measure not only total PSA, but another component called free PSA, which floats unbound in the blood.

但有些测试不仅仅会查总值，还会查到“游离PS A”值，会在血液中自由流动。

youdao

After the first month, in fact, the death rate among prostate-cancer patients during the PSA era was lower than it was among cancer-free men, according to the study.

CNN: STORY HIGHLIGHTS