ACKR3 and breast cancer: Significant associations were detected between higher CXCR7 expression level and worse OS of glioma (HR 1.77; 95% CI 1.43–2.19, p < 0.001) (Fig. 4a), breast cancer (HR 1.45; 95% CI 1.28–1.63, p < 0.001) (Fig. 4b), esophageal cancer (HR 2.72; 95% CI 1.11–6.66, p = 0.029) (Fig. 4c), and pancreatic cancer (HR 1.46; 95% CI 1.12–1.90, p = 0.006) (Fig. 4d).