Transcriptional regulation of the K15 keratin gene expression by IFN-γ. Constructs K15 wt-CAT, K15 340-CAT, and K14 wt-CAT were transfected into HeLa cells, which were then incubated in the presence or absence of IFN-γ. Fold increase due to IFN-γ is shown. Note that the negative control plasmid, K14 wt-CAT, is not regulated by IFN-γ.