The performance of the biosensor, therefore, has been investigated for its ability to detect various cancer markers, including human epidermal growth factor receptor 2 (HER2), doxorubicin (DOX), alpha-fetoprotein (AFP), Carcinoembryonic antigen (CEA), C-reactive protein, and prostate-specific antigen (PSA) [14,21,165]. The gene discussed is KLK3; the disease is cancer.