The length of study participation, tests and activities performed specifically for research will be determined by the enrollment group. Subjects in the Biopsy and Known Severe Liver Disease groups participate in the study for 5 years (enrollment and four annual follow-up visits). Both groups undergo a physical exam, diagnostic abdominal ultrasound, pulmonary function testing and the collection of serum, plasma and blood for routine laboratory and genetic testing (Induced Pluripotent Stem Cells (iPS cells), microRNA and DNA). However, only the Biopsy Group participants undergo a liver biopsy and FibroScan at enrollment, and again in Year 5. The liver tissue samples will help the researchers learn what causes liver disease in some patients and how the liver disease progresses.