PC-SPES is a herbal mixture formerly marketed as a complementary treatment for prostate cancer that includes extracts from Glycyrrhiza uralensis, the source of licochalcone A. Screening of the bioactivities of PC-SPES component herbs revealed that extracts from G. uralensis could suppress prostate cancer cell proliferation and reduce the expression of the androgen receptor and prostate-specific antigen [13]. Here, KLK3 is linked to prostate cancer.