“…However, some studies emphasized only on CEA as a marker (five articles)87–91 and several studies also introduced both CK20 and CEA as prognostic markers 92–96. In most articles, CK20 and/or CEA were accompanied by markers such as CK19,97–102 GCC,96,103,104 Prominin 1 (CD133),95,100,105,106 EPCAM,107–109 survivin,110,111 ProtM,112 mucin 1 (MUC 1),105 and mucin 2 (MUC 2),99 and telomerase reverse transcriptase (hTERT) 101,113,114…”