The abnormal accumulation of l‐2‐HG is closely associated with the occurrence and progression of l‐2‐hydroxyglutaric aciduria and various cancers.[10, 12, 13]l‐2‐HG produced in the cytosol should be transported into the mitochondria and then degraded by L2HGDH (Figure 6a). The gene discussed is L2HGDH; the disease is cancer.