ESR1 and breast cancer: This suggests a primary role of the CXCR7/CXCL11 chemokine axis in the response of OC cells to estrogen, bringing selectivity in targeting the CXCR7 axis compared to other ER‐positive gynecologic cancer cells, such as breast cancer cells which did not exhibit CXCR7 upregulation by estrogen (Boudot et al., 2011).