CXCL12 and breast cancer: Researchers successfully isolated and identified two myofibroblast subgroups, CAF-S1 and CAF-S4, from metastatic lymph nodes of breast cancer and found that the CAF-S1 subgroup stimulated breast cancer cell migration and EMT through the CXCL-12 and TGF-β pathway, while the CAF-S4 subgroup induced breast cancer cell invasion through the NOTCH signaling pathway [22].