Results: Analysis of microarray data through WGCNA, PPI and ssGSEA identified 16 obesity-related immune-critical genes, including IL7R, CD3E, CD2, CCR5, CD3D, MS4A1, TRAT1, SLAMF8, CCL3L1, SPP1, CCL5, IL2RG, CD3G, TLR8, ITK, and CCL3. The gene discussed is CCL3L3; the disease is obesity due to melanocortin 4 receptor deficiency.