PF4 and dengue disease: 85). As expected, P-selectin, PF4 and RANTES were among the highly upregulated factors in dengue (Ref. 85). Histones H2A and HLA class I were also upregulated in dengue-infected platelets. The binding of circulating histone H2A to the TLR4 receptor on platelets caused platelet activation that could be completely blocked by anti-histone H2A monoclonal antibody (Ref. 85).