Huh7.5 and Hu1b cells were infected with HCV-3a at MOI = 1 and harvested at 0 h, 6 h and 24 h p.i. In Figure 9(A1,A2), IFITM3 protein expression was shown to be up-regulated at 6 h post HCV-3a infection in both Huh7.5 and Hu1b cells, compared with non-infected cells (0 h), rendering IFITM3 a part of the host immune response mechanism against HCV entry. Here, IFITM3 is linked to infection.