The down-regulation of METTL14 leads to reduced fibroblast growth factor receptor 4 (FGFR4) mRNA decay through m6A RNA hypomethylation, thus initiating the β-catenin/TCF4-SLC7A11/FPN1 pathway to develop anti-HER2 resistance in breast cancer by attenuating ferroptosis.113. The gene discussed is FGFR4; the disease is breast carcinoma.