RET and pancreatic neoplasm: For example, RET activity in thyroid, breast and pancreatic cancers can enhance tumor expression of chemokine receptor CXCR4, triggering responses to circulating chemokines released by CAFs or the tumor itself, to recruit endothelial progenitors that promote angiogenesis to sustain the growing tumor mass (Castellone et al., 2004; Borrello et al., 2005; Lu et al., 2011; Werner et al., 2017; Wang et al., 2018).