GLS2 and malignant colon neoplasm: To further investigate the potential tumor suppressive role of Gls2, human liver cancer cells SMMC-7721 and human colon cancer cells HCT116 were transfected with either empty vector or 3 × Flag-tagged Gls2 expressing vector, and the Gls2 expression in SMMC-7721 and HCT116 cells was confirmed by western blotting (Figure 4A).