AD	Adenocarcinoma
BL	Blood
BM	Bone marrow
BMB-CCC	Biobank of Comprehensive Cancer Center North
cDNA	Complementary deoxyribonucleic acid
CI	Confidence interval
CK20	Cytokeratin-20
CRC	Colorectal cancer
CT	Computed tomography
CTC	Circulating tumor cells
DEFA5	α-defensin 5
DNA	Deoxyribonucleic acid
DTC	Disseminated tumor cells
EC	Esophageal carcinoma
EMT	Epithelial to mesenchymal transition
EU	Expression units
HER2	Human epidermal growth factor 2
HR	Hazard ratio
LQ	Likelihood quotient
MNC	Mononuclear cells
MRD	Minimal residual disease
mRNA	Messenger ribonucleic acid
n.s.	Not significant
OS	Overall survival
PBS	Phosphate-buffered saline
PET	Positron emission tomography
P2N	PopGen 2.0 Biobanking Network
RNA	Ribonucleic acid
ROC	Receiver operating characteristics
RT-PCR	Real-time-polymerase chain reaction
SCC	Squamous cell carcinoma
TCGA	The Cancer Genome Atlas
UICC	Union Internationale Contre le Cancer
UKSH	University Medical Center Schleswig-Holstein.