Bone marrow macrophage-derived miR-155 can be induced to release by the activators of pro-inflammatory M1 phenotype macrophages (LPS, IFN-α) and promote the secretion of inflammatory cytokines such as TNF-α, IL-12, thereby aggravating the inflammatory response in RA (Stanczyk et al., 2008), diabetes (Ying et al., 2017), and heart disease (Figure 3) (Heymans et al., 2013). Here, TNF is linked to rheumatoid arthritis.