Previously, our group conducted a series of meta-analyses to explore the clinical role of CTCs detected by RT-PCR in GC and CRC and summarized the commonly used markers for GC-CTCs (including CK19, CK20, CEA, hTerT, c-MET, MUC1, VEGFR-1, Survivin, uPAR, B7-H3, and STCs) and CRC-CTCs (including CK19, CK20, CEA, PLS3, CD133, hTerT, EphB4, LAMγ2, and MAT) detection (25, 49). Here, CEACAM5 is linked to colorectal carcinoma.