METTL3 and pneumonia: We comprehensively summarize METTL3 expression changes and related pathogenesis in inflammatory diseases, including atherosclerosis, myocardial infarction (MI), non-alcoholic liver disease, hyperuricemia (HUA), diabetes nephropathy, osteoarthritis (OA), intervertebral disc degeneration (IDD), rheumatoid arthritis, psoriasis, inflammatory bowel disease (IBD), sepsis, pneumonia, and tumor.