In response to CD3/CD28 stimulation, the secretion of TNF-α by CD8+ T cells trended towards positive correlation with BMI while IFN-γ secretion by CD8+ T cells significantly negatively correlated with BMI in young patients, suggesting an impairment of CD8+ T cells antiviral with obesity. The gene discussed is CD28; the disease is obesity due to melanocortin 4 receptor deficiency.