RETNLB and chronic obstructive pulmonary disease: Results suggested, compared with the control group, in BMDMs of COPD mice and RAW264.7 cells intervened by CSE, the mRNA expression levels of inflammatory factors and markers associated with M2 macrophages (CD206, Arg1, YM1, FizZ1, and IL-10) were increased (p<0.05, Figures 4 and 5), and the expression of iNOS was decreased (p<0.05, Figures 4 and 5).