METTL1-mediated metabolic reprogramming regulates the expression of key immune checkpoints, including PD-L1 and CTLA-4, and is associated with an immunosuppressive TME, reduced infiltration of activated T cells, and adverse clinical outcomes (58) In breast cancer, METTL1 expression is significantly elevated in tumor tissues compared to normal tissues, demonstrating diagnostic value. This evidence concerns the gene METTL1 and breast cancer.