METTL14 is a non-catalytic subunit of the METTL3-METTL14 heterodimer complex that catalyzes N6-methyladenosine (m6A) modifications on mammalian nuclear RNAs 1. Within this complex, METTL14 functions as the RNA-binding scaffold that recognizes substrates at consensus 5'-[AG]GAC-3' sites, while METTL3 provides catalytic activity 1. The m6A modification profoundly influences RNA metabolism, with reader proteins like YTHDFs primarily promoting mRNA degradation through cytoplasmic pathways 2. METTL14 regulates diverse biological processes including embryonic stem cell differentiation, cortical neurogenesis, and spermatogenesis through m6A-mediated mRNA destabilization 1. In disease contexts, METTL14 downregulation associates with colorectal cancer progression and poor survival; mechanistically, reduced METTL14 increases SOX4 mRNA stability via decreased m6A modification, promoting epithelial-mesenchymal transition and metastasis 3. Conversely, elevated METTL14 contributes to vascular aging through enhanced m6A modification of TLR4 mRNA, increasing inflammatory responses 4. Additionally, METTL14-dependent m6A methylation regulates mitochondrial function by promoting translation of nuclear-encoded mitochondrial complex subunits 5. METTL14 emerges as a context-dependent therapeutic target across multiple disease pathologies.