Obesity in humans reduces thymopoiesis. (A) Obesity in humans reduces thymopoiesis, quantitative PCR analysis of human sjTRECs in PBMCs shows significant correlation between reduction in TRECs with increasing BMI (30-40 years old). (B) The frozen PBMCs from additional (male and female; n = 30-35; age, 30-45 years) lean subjects were analyzed for TRECs and compared with overweight and obese subjects with and without T2D. All morbid obese (BMI > 45) subjects were insulin resistant.