Enhanced infection was inversely seen with dilution factors of anti-DenV2 sera obtained from BL/6, TLR2 KO, and MyD88 KO mice (Figure 6B and 6C), which indicates that anti-DenV2 sera from BL/6, TLR2 KO, and MyD88 KO mice could increase the infectivity of DenV2 and DenV4 in FcγR-bearing macrophages. This evidence concerns the gene TLR2 and infection.