GLS and neoplasm: Four weeks after inoculation, a marked decrease in tumor volume, along with a significant reduction in Ki67 positive tumor cells, were observed in mice implanted with GLS1 knockdown cells (Fig. 2H and I), We also performed TUNEL assays to determine apoptosis; however, no significant change was seen in apoptotic rate with or without GLS1 loss in xenograft tumors (data not shown).