TNF and chronic obstructive pulmonary disease: Li and his colleagues (19) recently found that MIR155HG was highly expressed in peripheral blood mononuclear cells of COPD patients compared with normal controls, and MIR155HG overexpression resulted in a significantly increased percentage of M1 macrophages accompanied by enhanced proinflammatory cytokine release (TNF-α, IL-1β and IL-12) as well as decreased M2 macrophage levels, whereas interference with MIR155HG expression reduced the ratio of M1/M2 macrophages (19).