SELP and infection: With regard to transcript changes related to thrombotic receptors and thrombotic properties of platelets, only mild increases in F2RL3 (coding for the thrombin receptor PAR4), P2RY1 or P2RX1 were observed with infection, in addition to SELP (coding for P-selectin) which is the selectin primarily responsible for mediating platelet-leukocyte interactions.