Fig. 1

C6orf15 expression is associated with metastasis. a Data from the TCGA database; 312 tissues from patients with colon cancer without distant metastasis and 58 tissues from patients with colon cancer with distant metastasis were selected for differential expression analysis. b Prediction based on the Starbase database suggests that the expression of C6orf15 is higher in colon cancer than in normal intestinal tissue. c and d The GEPIA database was used to analyse the relationship between high and low C6orf15 expression and disease-free survival as well as overall survival. e The TCGA database was used to analyse C6orf15 expression differences in different stages of colon cancer. f Protein expression of C6orf15 in cancer and paracancerous tissues from 13 colon cancer patients (Western blots). g Expression of C6orf15 in liver metastatic lesions as well as intestinal primary lesions of 6 colorectal cancer patients who developed liver metastases (Western blots). h C6orf15 mRNA expression in 48 clinical tissue samples (qRT-PCR); the difference in mRNA expression between cancerous and adjacent tissues was assessed in these 48 patients. i Immunohistochemical staining of liver metastatic lesions, intestinal primary lesions and paracancerous tissues from colon cancer patients to visualize the expression of C6orf15 in different tissues. j Immunofluorescence was used to show C6orf15 expression in liver metastatic foci as well as primary foci of colon cancer tissues (shown in red fluorescence); nuclei were counterstained with DAPI (blue). k Scoring of 150 pairs of clinical tissue samples after immunohistochemical staining and statistical analysis. For all statistical results, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, and ns (no statistical significance)