STAT3 and pulmonary fibrosis: Previous studies have shown a significant increase in the expression levels of IL-1β, IL-8, and IL-6 in BALF and lung tissue of pulmonary fibrosis patients and in animal models, and IL-1β or IL-6/IL-13 activation of JAK2 (Janus kinase 2) and STAT3 (Signal transducer and activator of transcription 3) stimulates primary AT2 and lung fibroblasts.