A Clinical Study to Map the HLA Genomic Region in the Greek Population

This study is creating a detailed genetic map of the HLA region (a set of genes important for immune function) in the Greek population. This information helps improve organ matching for transplants and understand disease risk in Greek people. **You may be eligible if...** - You are 18 or older with a Greek social security number - You are visiting a hospital, clinic, or private laboratory in Greece as part of regular care - You are willing and able to give written consent **You may NOT be eligible if...** - You are unable to provide written consent (for example, due to mental illness or incapacity) - You recently received a bone marrow transplant, stem cell transplant, blood transfusion (within the last 2 weeks), or liver transplant from another person - You have previously participated in this same study Talk to your doctor to see if this trial is right for you.