TNF and Arthritis: ,14,15,16 In further support of the clinical relevance of those URs, the expression of their downstream targets differed significantly between mild and severe arthritis in several cell types in joints: Tnf in fibroblasts (p = 2.00 × 10−3), Il1b in T cells (p = 4.14 × 10−5), Ltf in T cells (p = 9.51 × 10−5) and macrophages (p = 1.57 × 10−6), Dsc3 in macrophages (p = 9.9 × 10−7), and Mpz in macrophages (p = 1.84 × 10−14) (Figure S3; Data S4).