Accumulation of lactate in the tumor microenvironment (TME) significantly induces the expression of methyltransferase-like 3 (METTL3) in infiltrating myeloid cells in colon cancer mediated through H3K18 lactylation, which is essential for the transcription of immunosuppressive genes in TIM cells. Here, METTL3 is linked to malignant colon neoplasm.