CLDN4 and viral infectious disease: No significant effects of viral infection on mRNA levels of the selected genes were measured at any time point after HRV 16 infection, except for a significantly lower mRNA expression of claudin-4 after 48 h of HRV 16 infection in untreated, HRV 16-infected cells compared to IFN-β1a pre-treated, infected cells (figure S5a-c).