KLK3 and prostate cancer: Epidemiological data show that prostate cancer is more common in people aged 65 years and above, and its risk is influenced by multiple factors, including genetics, age, hormone levels, lifestyle, etc. Although prostate-specific antigen (PSA) testing has played a certain role in early screening and diagnosis, its specificity and sensitivity are limited, and there is still a need to find more effective molecular biomarkers to achieve early diagnosis and treatment and reduce the disease burden (1, 2).