Several studies have demonstrated that angiogenesis is highly dysregulated in RA, which is associated with increased differential expression of pro-angiogenic factors in synovial fluid and tissue such as VEGF, Angiopoietin 1/2, PlGF, PDGF or TGFβ1, that can promote either immature or mature stable vessels [11]–[18]. Here, ANGPT1 is linked to rheumatoid arthritis.