2. Study procedures The study is a longitudinal study following the follow-up schedule of the current standard of care for such lesions, i.e., once per 6 months and comparative biopsy once per 2-3 years. The important time points are initial visit (baseline), at the end of second, 5th and 8th year of follow up visits. However, the time of biopsy is solely based on the clinical judgment of the clinicians, i.e., signs of disease progression.