They’re not only secreted by tumor cells but also by stromal and immune cells, actively participating in modulating the immune response against the tumor [71,72] When the chemokine CXCL12 binds to the chemokine receptor CXCR4, it triggers activation in both the MAPK and the PI3K/AKT/mTOR pathways, extending the survival and promoting the dissemination of tumor cells [73]. Here, CXCR4 is linked to neoplasm.