KRAS and cancer: Since the information about KRAS mutations, demographic and clinical characteristics (gender, drinking history, smoking history, family history of cancer, clinical diagnosis, anatomical staging, tumor differentiation, and distant metastasis), and the serum concentrations of 18 TEs were all acquired from the KRAS-positive group (n=81) and the KRAS-negative group (n=81), we explored their correlations by Spearman correlation analysis.