Phosphorylation at serine 63 of the transcription factor c-Jun, a component of the activating protein-1 (AP-1) transcriptional complex was observed in response to Ad-eIF5A1 infection (Additional file 1: Figure S1), which is consistent with activation of SAPK/JNK [20] in response to eIF5A1. This evidence concerns the gene MAPK9 and infection.