After virus infection, higher levels of phosphorylated-smad2/3 and lower levels of smad7 were found in WSN-infected A549 cells than in Yamagata-infected A549 cells (Figures 5A–C), indicating that WSN trigged a stronger TGF-β/smad2 signaling pathway than Yamagata. The gene discussed is SMAD2; the disease is viral infectious disease.