In BALB/c MSCs, cell proliferation was reduced after infection by IL-4 (MSCs-IL4) and the control (MSCs-V) vectors, compared to MSCs; however, cell proliferation was significantly enhanced in MSCs-PDGF and MSCs-IL-4-PDGF groups compared to MSC-IL4 group (Fig. 3A, B). This evidence concerns the gene IL4 and infection.