TREM1 and chronic obstructive pulmonary disease: In line with this, cigarette smoke-induced exosomal lncRNA MEG3 has been demonstrated to drive M1 polarization and pyroptosis through the SPI1/METTL3/TREM-1 axis, highlighting another pathway by which environmental exposures exacerbate macrophage dysregulation in COPD (Wang L. et al., 2024).