A later study evaluating the effects of P. aeruginosa secreted factors on primary CF and non-CF airway cells observed no effect of pre-treatment on RV load or antiviral gene expression; however, pre-exposure of cells to P. aeruginosa secreted factors did potentiate IL-8 production upon subsequent RV infection (90). This evidence concerns the gene CXCL8 and cystic fibrosis.