As the core member of the STAT protein family, STAT3 plays a with versatile roles in the inflammatory response and tumor progression. Multiple growth factors and cytokines are implicated in the canonical STAT3 pathways, regulating the transcription of STAT3 target genes and downstream cellular processes such as cell differentiation, angiogenesis, and tumorigenesis [258]. The dysregulated STAT3 signaling has been implicated in a series of inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease [259]. The gene discussed is STAT3; the disease is rheumatoid arthritis.