U-13C glutamine tracing studies revealed that SLC1A5 expression was sufficient to restore the glutamine-derived reductive metabolites m + 3 aspartate, m + 3 malate, and m + 3 fumarate in FTO knockdown cells, indicating that SLC1A5 is an important FTO target driving glutamine-driven reductive carboxylation in ccRCC cells (Fig. 4B). The gene discussed is FTO; the disease is nonpapillary renal cell carcinoma.