GCLM and hepatocellular carcinoma: To test the role of NO on glutathione, we incubated human hepatocellular carcinoma derived Huh7 cells with NO donor S-nitroso-N-acetylpenicillamine (SNAP) versus vehicle (DMSO) control and observed a significant increase in mRNA expression of both GCL subunits, GCLC (Figure 7F) and GCLM (Figure 7G).