Non-essential serine is diverted into glycolysis, whereas glutamine fuels the tricarboxylic acid cycle via glutaminolysis in cancer cells, including HCT116 cells.26, 27, 31 Reducing either amino acid, particularly glutamine, over 4 h had a stronger inhibitory effect on 4E-BP1 hyperphosphorylation compared with loss of any essential amino acid (Figure 6a). The gene discussed is EIF4EBP1; the disease is cancer.