AREG and arthritic joint disease: The arthritis-associated genes are BLR, G protein-coupled receptor; RAB33A, Small GTPases - (Rho) GTPase activating proteins; the chemokine gene CCL19; the cell growth associated genes AREG and EGF; the B cell marker gene CD19; the tumor suppressor gene FLCN1; BPI, which is associated with anti-microbial activity; SPP1, an epithelial-mesenchymal transition and Inflammation marker; and innate immune responses related genes, CXCL13, SOCS1 and TAP1—the first is a myeloid associated gene, whilst the last two are IFN signaling genes.