PF4 and Sepsis: While S. aureus infection of mice harboring platelet-specific deletion of ADAM10 through PF4-mediated Cre recombinase expression (PF4 ADAM10–/–) is associated with a reduction in platelet aggregation within the liver (21) and improved intravascular hemostasis (12), these mice succumb to lethal sepsis unless ADAM10 is concurrently deleted in the myeloid cell lineage through expression of Cre recombinase under the control of the Lyz2 promoter (12).