Mechanistically, T3-activated TRβ interacts with PGC1α to transcriptionally upregulate PGC1α, UCP1, and mitochondrial fusion genes OPA1 and MFN2, thereby enhancing mitochondrial activity, promoting lipid utilization, and suppressing ccRCC progression. The gene discussed is MFN2; the disease is nonpapillary renal cell carcinoma.