The CXCL12-enhanced chemotaxis of triple negative breast cancer cells (MDA-MB-231) was inhibited in a mixture of CXCL4 and CXCL12 chemokines [24], and CXCL4 counteracted CXCL12-induced ERK (extracellular signal-regulated kinase) phosphorylation in lymphatic and microvascular endothelial cells [185]. This evidence concerns the gene PF4 and triple-negative breast carcinoma.