COL3A1 and rectal cancer: GUCA2A were downregulated in both colon cancer (− 0.38-fold, p-value: 0.003) and rectal cancer (− 0.49-fold, p-value: 0.1) compared with normal tissues and COL3A1 showed upregulated expression in both colon cancer (5.58-fold, p-value: 0.0001) and rectal cancer (14.29-fold, p-value: 0.0004) compared with normal tissues (Fig. 10).