FTO is an RNA N6-methyladenosine (m6A) demethylase that serves dual roles in metabolism and cancer biology. Primary Function: FTO catalyzes oxidative demethylation of m6A, the most prevalent internal mRNA modification in eukaryotes, affecting mRNA stability and expression 1. It also demethylates m6A in tRNAs and snRNAs, including the m6A cap structure (m6A(m)) 2. Mechanism: FTO's enzymatic activity regulates adipogenesis and energy homeostasis by modulating expression of metabolic genes 3. In disease contexts, FTO promotes tumorigenesis through m6A demethylation of oncogenic targets including MYC and HSF1, enhancing their expression in acute myeloid leukemia and multiple myeloma 45. Disease Relevance: Genome-wide association studies identified FTO polymorphisms associated with obesity and multiple cancers including breast, pancreatic, and endometrial cancer 3. FTO upregulation drives progression in clear cell renal cell carcinoma and hepatocellular carcinoma through m6A-mediated pathways 67. FTO also impacts ferroptosis regulation, influencing both cardiotoxicity and NAFLD pathogenesis 89. Clinical Significance: FTO inhibitors (FB23-2) demonstrate therapeutic potential in AML and ccRCC xenograft models, suggesting FTO as a druggable oncology target 106.