(Li et al., 2015; Wang and Kan, 2021; Xu et al., 2021) For instance, prostate-specific antigen (PSA) is considered to be the most effective biomarker for clinical diagnosis of prostate-related diseases (e.g. rostatitis, enlarged prostate, nephritis, prostate polyps, and prostate cancer) because it can specifically reflect the condition of the prostate. The gene discussed is KLK3; the disease is prostate cancer.