These 16 genes (IL7R, CD3E, CD2, CCR5, CD3D, MS4A1, TRAT1, SLAMF8, CCL3L1, SPP1, CCL5, IL2RG, CD3G, TLR8, ITK, CCL3) were thus initially identified as immune-critical genes associated with obesity and used for subsequent analysis. The gene discussed is TRAT1; the disease is obesity due to melanocortin 4 receptor deficiency.