RecruitingKidney Function in People With Cystic Fibrosis in the Era of HEMTThe purpose of this study is to find out what causes kidney disease in people with CF. The investigators will study biomarkers in the blood and urine that can either predict who is at risk or detect kidney damage early before it becomes permanent. The study will compare these markers in people with CF over time and during the treatment of lung flare-ups. It will also compare the blood and urine samples obtained from people without CF. The comparison aims to better understand the impact of cystic fibrosis and its treatment on the kidneys, as well as to develop improved methods for preventing, diagnosing, and treating kidney issues associated with CF.