Migration of blood-derived leukocytes to tissue sites of inflammation is a hallmark of the
response that the host organizes to counteract an insult or a trauma or an infection. A
cascade of events is then activated to allow interaction between the leukocyte and the
endothelium of postcapillary venule, and this cascade is finely regulated such that
mechanisms of negative control are operating side by side with pathways that promote and
sustain the extravasation process. Examples of both these positive and negative regulatory …