Some studies in vitro have also found that SDF-1/CXCR7 enhanced the migration and invasion abilities of cancer cells, including liver cancer (Neve Polimeno et al., 2015), pancreatic cancer (Guo et al., 2016), kidney cancer (Ierano et al., 2014), breast cancer (Wani et al., 2014), ovarian cancer (Yu et al., 2014), glioma (Liu et al., 2013), and papillary thyroid carcinoma (Liu et al., 2014). Here, ACKR3 is linked to breast cancer.