TNF and rheumatoid arthritis: Consistent with these data, the combination of NG2 glia ablation and LPS challenge significantly elevated the levels of pro-inflammatory mediators, which are associated with cytokine and cytokine receptor interactions, the toll-like receptor signaling pathway, the Tnf signaling pathway, the NFκB family, and the rheumatoid arthritis and NOD-like receptor signaling pathway, compared with LPS alone (Fig. 3g and Additional file 1: Figure S6b).