Consequently, infection by heterogeneous PRRSV strains was markedly inhibited in S100A4-transfected MARC-145 cells compared to inhibition observed for EV-transfected cells measured by Anti-N Mab-6D10 except for PRRSV-1 strains due to the antigenic variation of N protein (Figure 10E). This evidence concerns the gene S100A4 and infection.