For instance, in human breast carcinomas, Orimo et al. revealed that resident CAFs overexpressed stromal cell-derived factor 1 (SDF-1), simultaneously recruiting endothelial progenitor cells to accelerate angiogenesis and directly stimulating carcinoma proliferation via C-X-C chemokine receptor type 4 (CXCR4) 3. Here, CXCR4 is linked to breast carcinoma.