These no longer solely serological kits (Accu-Tell CEA Rapid Test Cassette, rapid prostate cancer test by Zhejiang Orient Gene, etc.)have evolved into direct PCR-based tools (lung cancer rapid diagnostic test by Lepu Medical Technology, cancer rapid diagnostic test by SPACEGEN, etc.)and nucleic acid-based LFAs (NABLFAs), which combine molecular detection and the principles of immunochemical visualization [20,21]. The gene discussed is CEACAM5; the disease is cancer.