The differences in viral mRNA detected in Calu-3 cells at 15 min to 72 h pi with RSV-A2, rA2-GC12 and rA2-GC4 reveal that the differences in TEER do not correlate with differences in RSV entry or early replication in Calu-3 cells, and suggest that the differences in TEER and viral production following infection with the CCR mutant viruses are not the result of changes in the ability of the CX3C mutant viruses to interact with CX3CR1. This evidence concerns the gene CX3CR1 and infection.