In a glioblastoma study, it was suggested that SIRT4 might indirectly inhibit Gln production by reducing GS levels20; in addition to this, SIRT4 can also upregulate GLS levels in colon cancer cells,34 which catalyze the deamination of Gln to produce Glu and NH4+.32 The gene discussed is SIRT4; the disease is malignant colon neoplasm.