In contrast, no significant association was found between obesity and LTBI based on the QFT results (aOR = 0.58, p = 0.134), although a weak positive correlation was detected between BMI and IFN-γ levels (Spearman’s r = 0.06, p = 0.019; Supplementary Figure S2), suggesting limited biological relevance of BMI to IFN-γ variation. The gene discussed is IFNG; the disease is obesity due to melanocortin 4 receptor deficiency.