The network was originally funded in 2000 and has been extended through June 2010 to perform interventional clinical trials in key areas of thalassemia care. Two major trials are proposed: First, a randomized, controlled trial to examine the effect of DFO alone versus DFO plus deferiprone on cardiac disease due to transfusional iron overload; second, a randomized trial of arginine versus sildenafil for pulmonary hypertension, an important problem in thalassemia intermedia and other hemolytic states. Goals are to provide an infrastructure for development, launch, and prompt completion of small, innovative trials in thalassemia and to improve assessment of phenotype and clinical outcomes in thalassemia to facilitate current and future clinical trials. This will be accomplished by two studies: The Thalassemia Longitudinal Cohort (TLC) study and the Iron Burden Study, which is a detailed study of iron-related organ damage comparing measures of iron burden in the heart, liver, and pancreas to outcomes of iron-related organ dysfunction. Combined with the clinical trials and the ability to perform detailed genotype/phenotype correlations, these improved phenotype and outcome measures are powerful tools to enhance knowledge about thalassemia clinical care. Please refer to individual Clinicaltrials.gov study listings for TCRN study specifics and current information about trials, eligibility, and site participation. Thank you.