TNF and systemic lupus erythematosus: Another small subset of patients with SLE (four out of 20 patients) did not have the interferon-inducible signature but instead had upregulation of gene expression levels in a group of genes which encode largely for chemokines (CXCL2, CCL3, CCL14, and CCL20) and other soluble pro-inflammatory molecules: tumor necrosis factor, interleukin-1 (IL-1), and IL-6.