In vitro studies revealed that in breast cancer CrkL plays a regulatory role in the stromal cell-derived factor 1 (SDF-1), induced Erk1/2, and phosphatidylinositol 3-kinase/Protein Kinase B (PI3K/Akt) pathways, which are directly linked to the invasion and migration of breast cancer cells [24]. This evidence concerns the gene CXCL12 and breast cancer.