DKK1 and breast cancer: Moreover, astrocytic Dickkopf Wnt signaling pathway inhibitor 1 (DKK1) was overexpressed and stimulated brain metastatic BC cell migration by increasing in gene expression of fibroblast growth factor 13 (FGF-13), known to be promote metastasis of the aggressive TNBC (Johnstone et al., 2020), and phospholipase C beta 1 (PLCB1), also upregulated in highly metastatic BC cells (Sengelaub et al., 2016).