TGFB1 and infection: In addition, it was found that the JNK signaling is unlikely to be responsible for such an enhancement effect, as the presence of its inhibitor, SP600125, in the TGF-β1 treatment resulted in unsuccessful infection of RuV in A549 cells, with the percentages of RuV-positive cells decreasing to almost 0%, while an increase in virus binding was observed (Figure 5).