GLUL and neoplasm: To determine whether the increased tumor burden in Glul-KO livers was due to either early tumor initiation or progression, we injected oncogenes into Glulfl/fl mice first via SB-HTVI and then injected adenoviral GFP or adenoviral Cre via the tail vein to knock out GS expression 7 days after oncogene induction (Figure 1G).