Those studies using RT-PCR to detect tumor cells in LNs amplified fragments for different RNA markers, i.e., KRT19 (CK19), CEACAM5 (CEA), forkhead box A1 (FOXA1), SAM-pointed domain containing ETS transcription factor (SPDEF), tumor-associated calcium signal transducer 2 (TACSTD-2), mucin 1 (MUC1), and MGB1 [22]. The gene discussed is CEACAM5; the disease is neoplasm.