To investigate whether proteasome inhibitor MG132, which inhibits degradation of IκBα, affected replication of RSV, expression of claudin-4 and occludin, and production of proinflammatory cytokines, HNECs were pretreated with 0.1–10 μg/ml MG132 30 min before infection with RSV at an MOI of 1 for 24 h. This evidence concerns the gene CLDN4 and infection.