UCK1 and lung cancer: To reveal the kinase responsible for RX-3117 phosphorylation, RNA interference (RNAi) experiments were performed targeting UCK1 and UCK2 mRNA with short interfering RNAs (siRNAs) in combination with chemosensitivity assays to assess whether UCK1 and UCK2 down regulation at RNA level had an effect on the sensitivity of lung cancer cells to RX-3117.