STAT1 and viral infectious disease: To understand the mechanism of upgrading viral propagation when using these inhibitors, we first detected some pivotal markers that regulate anti-viral responses, including interferon Regulatory Factor 9 (IRF9) and phosphorylated signal transducer and activator of transcription 1 (p-STAT1).35 The results indicated that viral infection activated the anti-viral response, manifesting as the upregulation of IRF9 and p-STAT1.