12. Adequate liver function as assessed by total bilirubin ≤ 1.5x upper limit of normal (ULN), and alanine transaminase (ALT) and aspartate transaminase (AST) ≤ 2.5x ULN (≤ 5.0x ULN in the case of liver metastases). Patients with known Gilbert's syndrome may be enrolled with total bilirubin ≤ 3.0 mg/dL.