Long non-coding RNA ITSN1-2(lncRNA ITSN1-2) promotes fibroblast-like synovicytes (FLS) proliferation and suppress apoptosis through activation of the NOD2/RIP2 signaling pathway, thereby exacerbating synovitis in Rheumatoid arthritis (RA) pathology. The gene discussed is ITSN1; the disease is rheumatoid arthritis.