Inclusion Criteria:

- Subject and/or parent guardian must be able to understand and provide informed
consent;

- Is the recipient of a living or deceased donor liver tx when subject was less than or
equal to 6 years of age;

- Is at least 4 years post-tx at the time of study enrollment;

- Has normal allograft function defined as Alanine aminotransferase (ALT) < 50 IU/l and
gamma-glutamyl transferase (GGT) < 50 IU/l;

- Has no evidence of AR or CR within the past 2 years, based on medical history;

- Is stable on IS monotherapy with a calcineurin inhibitor (CNI);

- For female subjects of childbearing potential, subject must have a negative pregnancy
test upon study entry;

- For female and male subjects with reproductive potential, subject must agree to use
FDA approved methods of birth control for the duration of the study;

- Must be negative for HBV and HCV infection within one year of enrollment;

- Must have screening biopsy that fulfills, based on central pathology reading,

Exclusion Criteria:

- Have received a liver tx for autoimmune liver disease, including autoimmune hepatitis
or primary sclerosing cholangitis;

- Have received a liver tx for hepatitis B or hepatitis C;

- Have received a second organ transplant before, simultaneously, or after liver tx;

- Have a calculated GFR (modified Schwartz formula) of less than 60 mL/min/1.73 m2;

- Have had a 50% dose increase in CNI within 6 months of screening;

- Have discontinued a second IS agent within 12 months of screening;

- Have any systemic illness requiring or likely to require chronic or recurrent use of
IS;

- Is pregnant or breastfeeding;

- Is unwilling or unable to adhere with study requirements and procedures;

- Have mental illness or history of drug or alcohol abuse that, in the opinion of the
investigator, would interfere with the participant's ability to comply with study
requirements;

- Is unwilling or unable to provide consent or comply with the study protocol;

- Has used investigational drugs within 4 weeks of enrollment;

- Is receiving treatment for HIV infection;

- Has received any licensed or investigational live attenuated vaccine(s) within two
months of enrollment;

- Has any medical condition that, in the opinion of the investigator, will interfere
with safe participation in the trial.