PDIA4 and infection: Furthermore, knocking-down the expression of PDIA4 in Caco-2 cells by transfection with a pool of specific siRNAs directed to its mRNA (Figure 4D) reduced the infectivity of HAstV-8 by about 60% as compared to a control transfection with an irrelevant scrambled siRNA, indicating the involvement of PDIA4 in the infection of this virus (Figure 4C); on the other hand, as expected, the infectivity of HAstV-2 was not affected by the siRNAs.