PCLAF and infection: Upon infection, keratinocytes, epithelial cells, tissue resident macrophages, anddendritic cells produce several soluble agents such as lipid mediators(platelet-activating factor (PAF), leukotriene B4 (LTB4), etc.), and severalcytokines (IL-1, IL-8, IL-17, TNFα, etc.), which along with agents released bythe pathogen (LPS, toxins, etc.), induce endothelial cell stimulation [6-8].These agents promote the expression of E- and P-Selectins on the surface ofendothelial cells.