Fig. 1. High expression of CXCR7 promotes CAF activation in metastatic CRC.

A, B Expression of α-SMA and CXCR7 was analyzed by IHC in paired human CRC tissues (metastatic and non-metastatic CRC) and the corresponding adjacent normal colonic tissues (n = 24, scale bar = 200, 50 μm). C Relative expression of CXCR7 and α-SMA in different groups was semi-quantified of mean density (IOD/area) using image-pro plus 6 software. *p < 0.05, **p < 0.01. D Box plots showed the relative expression of CXCR7 at different pathological stages and were performed by Gene Expression Profiling Interactive Analysis (GEPIA). Relative expression of CXCR7 was shown as log₂ (TPM + 1), TPM represents transcripts per million. E, F The correlation of expression of CXCR7 (log₂ CXCR7 TPM) with expression of α-SMA (log₂ ɑ-SMA TPM) and FAP (log₂ FAP TPM) was determined in CRC tissues by GEPIA. TPM represents transcripts per million. G, H The association of the expression of CXCR7 (ACKR3) with overall survival was analyzed by GEPIA using TCGA datasets in gastrointestinal cancer patients (COAD plus STAD) and CRC patients (COAD). The patients were divided with high and low gene expression levels using the median cutoff and log-rank p value was shown. COAD colonic adenocarcinoma; STAD stomach adenocarcinoma.