KLK3 and neoplasm: The multi-tumor marker protein chip developed in China was used for the early diagnosis and monitoring of tumors by analyzing the content of 12 common tumor markers (carbohydrate antigen 199 (CA199), neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), carbohydrate antigen 242 (CA242), ferritin (FER), β-HCG, alpha fetoprotein (AFP), prostate-specific antigen (PSA), free-PSA, carbohydrate antigen 125 (CA125), human growth hormone (HGH), and carbohydrate antigen 153 (CA153); Sun et al., 2004).