Splenic weight and iron deposition in chimeric hemoglobinopathy mice following IUHCT + postnatal BMT. Spleens from chimeric SCD (n = 4) and Thal (n = 5) mice who had undergone a postnatal “booster” transplant were harvested at 40 weeks of age and their weight was compared with age-matched naïve SCD mice (n = 6), Thal mice (n = 7), B6 WT (n = 6), and B6 WT chimeric mice boosted following 138 cGy TBI (n = 4). *P < .05 vs corresponding naïve SCD or Thal mice (A-B). Spleens were evaluated by histology for iron deposition in chimeric Thal mice following postnatal BMT and compared with age-matched naïve Thal and chimeric B6 WT controls (C).