We selected pre-infection, acute illness, and convalescent PBMC samples collected from four previously flavivirus naïve patients infected with an attenuated DENV-3 challenge virus and assessed the expression of Fc-receptors FcγRIIa (CD32), FcγRI (CD64), and FcaR (CD89) on PBMC monocytes by flow cytometry. This evidence concerns the gene FCAR and infection.