TGFB1 and rheumatoid arthritis: Based on our microarray analysis discussed later in this manuscript and given that TGFβ and BMP contribute to the pathogenesis of rheumatoid arthritis (RA), and TGFβ/BMP generally regulate endochondral bone formation [9, 12–14], we manually curated a list of 27 genes related to TGFβ/BMP signaling including Smads, BMP ligands and receptors, and TGFβ ligands and receptors to examine this prominent signaling pathway in JFLS using Ingenuity Pathway Analysis (IPA).