KRT20 and colorectal carcinoma: Although the expression of both genes has been described predominantly in the gastrointestinal tract according to the Human Protein Atlas (https://www.proteinatlas.org/ (accessed on 24 February 2022)) [41], and RNA-sequencing data in the Cancer Genome Atlas (TCGA) database indicate that the expression of either gene is not altered in EC compared to the normal tissue [42], CK20 was chosen as a biomarker for EC cells, because it has already been proven as a good indicator for CTC and DTC in CRC and EC patients with a high prognostic and predictive value [19,21,32].