The KEGG pathways of the CXCL16 high-expression group were mainly enriched in linoleic acid metabolism and fatty acid metabolism, and in the CXCL16 low-expression group of obesity, the pathways were mainly enriched in other glycan degradation and toll-like receptor signalling pathways (Fig. 6C). Here, CXCL16 is linked to obesity due to melanocortin 4 receptor deficiency.