KLK3 and neoplasm: Numerous tumor-specific promoters have been explored, including human telomerase reverse transcriptase promoter (hTERT), hypoxia response element (HRE) promoter, prostate-specific antigen promoter (PSA), alpha-fetoprotein promoter (AFP), alpha-lactalbumin promoter (ALA), and mucin 1 promoter (DF3/MUC1).