In the case of activation of platelets as a result of a bacterial infection, these cells, among others, affect the CXCL4 (PF-4) and CCL5 (RANTES) chemokine receptors on the surface of the vascular endothelium, induce "extravasation" of leukocytes (29, 30, 38, 62, 81). This evidence concerns the gene PF4 and bacterial infectious disease.