Expression of human and mouse ISG12 genes in cell lines. Transcripts for the indicated human and mouse ISG12 genes were detected by RT-PCR. RNA was isolated from the human HT1080 cells (a) or mouse L-929 cells (b) treated with (left hand panels) or without (right hand panels) type I IFN for 24 h. The indicated serial five-fold dilutions of reverse transcripts were analysed by PCR. Most PCR assays included, as an internal control, primers for beta-actin (β-Ac). Diagnostic products for each transcript are arrowed. M = size markers.