GPT and Biliary tract obstruction: We further determined the serum levels of glutamate pyruvate transaminase (GPT) and glutamic oxaloacetate transaminase (GOT) (markers of liver toxicity), blood urea nitrogen (BUN), and creatinine (markers of kidney toxicity), alkaline phosphatase (ALP) (a marker of bile duct obstruction), blood glucose (a marker of metabolic disorder), and total protein (TP) and albumin (ALB) (markers of systemic inflammation) in vehicle-treated and gracillin-treated mutant-Kras mice to determine potential toxicities after long-term treatment with gracillin.