Prostate-specific antigen (PSA), alpha-fetoprotein (AFP), CEA, cancer antigen (CA) 125 and 15-3, pseudopodium-enriched-atypical kinase one (PEAK1), and serum cytokeratin fragment 21.1 (Cyfra 21.1) offer excellent biorecognition of prostate, liver, lung, ovarian and breast, pancreatic, and oral cancers, respectively [173–176]. Here, KLK3 is linked to lip and oral cavity carcinoma.