CXCR4 and skin basal cell carcinoma: In addition, the authors found that Tac-1 KD, which is associated with reduced expression of both SDF-1α and CXCR-4, was able to impair adhesion and transmigration and that re-expression of CXCR-4 (but not SDF-1α) in Tac-1 KD cells partly (MDA-231) or completely (TD47) restored BCC ability to migrate through the endothelial monolayer [44].