MAVS and neoplasm: Through RNA sequencing, point mutations, MB49 mouse tumor models, and single-cell RNA sequencing, we demonstrated that high methionine levels elevate the expression of m<sup>6</sup>A reader YTHDF1, promoting the degradation of RIG-I, thereby inhibiting the RIG-I/MAVS-mediated IFN-I pathway and reducing the efficacy of tumor immunotherapy.